Use the following answers for questions 1 - 3 · Web viewThe volume of distilled water that...

AP MULTIPLE CHOICE PROBLEMS

A QUESTION YR

CH TOPIC

EADC

4. Use the following answers for questions 4 - 7.(A) Hydrofluoric acid(B) Carbon dioxide(C) Aluminum hydroxide(D) Ammonia (E) Hydrogen peroxide 4. Is a good oxidizing agent5. Is used to etch glass chemically6. Is used extensively for the production of fertilizers7. Has amphoteric properties

1984

??? Misc.

B 63. Which of the following characteristics is common to elemental sulfur, chlorine, nitrogen, and carbon?(A) They are gaseous elements at room temperature.(B) They have oxides that are acid anhydrides.(C) They have perceptible color at room temperature.(D) They form ionic oxides.(E) They react readily with hydrogen at room temperature.

1989

??? Genl Info

E 64. A solution is known to contain an inorganic salt of one of the following elements. The solution is colorless. The solution contains a salt of(A) Cu(B) Mn(C) Fe(D) Ni(E) Zn

1989

??? Genl Info

CDA

11. Questions 11-13(A) Pb(B) Ca(C) Zn(D) As(E) Na 11. Utilized as a coating to protect Fe from corrosion12. Is added to silicon to enhance its properties as a semiconductor13. Utilized as a shield from sources of radiation

1994

??? Genl Info

Kim Duncan [email protected] School Science Teacher 703-584-2204Flint Hill School

AP MULTIPLE CHOICE PROBLEMSCEBA

1. Questions 1-4 refer to the following types of energy. (A) Activation energy(B) Free energy(C) Ionization energy(D) Kinetic energy(E) Lattice energy 1. The energy required to convert a ground-state atom in the gas phase to a gaseous positive ion 2. The energy change that occurs in the conversion of an ionic solid to widely separated gaseous ions 3. The energy in a chemical or physical change that is available to do useful work 4. The energy required to form the transition state in a chemical reaction

1999

??? Genl Info

D 59. When 70. milliliter of 3.0-molar Na2CO3 is added to 30. milliliters of 1.0-molar NaHCO3 the resulting concentration of Na+ is (A) 2.0 M(B) 2.4 M(C) 4.0 M(D) 4.5 M (E) 7.0 M

1984

04

06 TES

TSolns

B 67. A student wishes to prepare 2.00 liters of 0.100-molar KIO3 (molecular weight 214). The proper procedure is to weigh out (A) 42.8 grams of KIO3 and add 2.00 kilograms of H2O(B) 42.8 grams of KIO3 and add H2O until the final homogeneous solution has a volume of 2.00 liters(C) 21.4 grams of KIO3 and add H2O until the final homogeneous solution has a volume of 2.00 liters(D) 42.8 grams of KIO3 and add 2.00 liters of H2O(E) 21.4 grams fo KIO3 and add 2.00 liters of H2O

1984

04

06 TES

TSolns

B 68. A 20.0-milliliter sample of 0.200-molar K2CO3 solution is added to 30.0 milliliters of 0.400-molar Ba(NO3)2 solution. Barium carbonate precipitates. The concentration of barium ion, Ba2+, in solution after reaction is(A) 0.150 M(B) 0.160 M(C) 0.200 M(D) 0.240 M(E) 0.267 M

1984

04RxnsPreci

p

B 69. What is the mole fraction of ethanol, C2H5OH, in an aqueous solution in which the ethanol concentration is 4.6 molal?(A) 0.0046(B) 0.076(C) 0.083(D) 0.20(E) 0.72

1984

04 Solns


AP MULTIPLE CHOICE PROBLEMSC 15. The weight of H2SO4 (molecular weight 98.1) in 50.0 milliliters

of a 6.00-molar solution is(A) 3.10 grams(B) 12.0 grams(C) 29.4 grams(D) 294 grams(E) 300. grams

1989

04

04/05

TEST

Solns

C 26. How many milliliters of 11.6-molar HCl must be diluted to obtain 1.0 liter of 3.0-molar HCl?(A) 3.9 mL(B) 35 mL(C) 260 mL(D) 1,000 mL(E) 3,900 mL

1989

04

06 TES

TSolns

A 43. Which of the following does NOT behave as an electrolyte when it is dissolved in water?(A) CH3OH(B) K2CO3(C) NH4Br(D) HI(E) Sodium acetate, CH3COONa

1989

04

04/05

TEST

Solns

A 72. How many moles of solid Ba(NO3)2 should be added to 300. milliliters of 0.20-molar Fe(NO3)3 to increase the concentration of the NO3¯ ion to 1.0-molar? (Assume that the volume of the solution remains constant.)(A) 0.060 mole(B) 0.12 mole(C) 0.24 mole(D) 0.30 mole(E) 0.40 mole

1989

04Rxns

‘

E 28. Given that a solution is 5 percent sucrose by mass, what additional information is necessary to calculate the molarity of the solution?I. The density of waterII. The density of the solutionIII. The molar mass of sucrose(A) I only(B) II only(C) III only(D) I and III(E) II and III

1994

04 Solns


AP MULTIPLE CHOICE PROBLEMSD 47. Which of the following has the lowest conductivity?

(A) 0.1 M CuS04(B) 0.1 M KOH(C) 0.1 M BaCl2(D) 0.1 M HF(E) 0.1 M HNO3

1994

04

04/05

TEST

Solns

E 53. If 87 grams of K2 SO4 (molar mass 174 grams) is dissolved in enough water to make 250 milliliters of solution, what are the concentrations of the potassium and the sulfate ions? [K+] [SO42¯] (A) 0.020 M 0.020 M

(B) 1.0 M 2.0 M

(C) 2.0 M 1.0 M

(D) 2.0 M 2.0 M

(E) 4.0 M 2.0 M

1994

0404/0

5 TES

T Solns

C 33. A 1.0 sample of an aqueous solution contains 0.10 mol of NaCl and 0.10 mol of CaCl2. What is the minimum number of moles of AgNO3 that must be added to the solution in order to precipitate all of the Cl¯ as AgCl(s) ? (Assume that AgCl is insoluble.) (A) 0.10 mol(B) 0.20 mol(C) 0.30 mol(D) 0.40 mol(E) 0.60 mol

1999

04

04/05

TEST

RxnsPreci

p

A 56. A yellow precipitate forms when 0.5 M NaI(aq) is added to a 0.5 M solution of which of the following ions? A) Pb2+(aq)B) Zn2+(aq)C) CrO42¯(aq)D) SO42¯(aq)E) OH¯(aq)

1999

04

06 TES

TSolnsPreci

p

C 59. A 40.0 mL sample of 0.25 M KOH is added to 60.0 mL of 0.15 M Ba(OH)2. What is the molar concentration of OH¯(aq) in the resulting solution? (Assume that the volumes are additive) A) 0.10 MB) 0.19 MC) 0.28 MD) 0.40 ME) 0.55 M

1999

04

06 TES

TSolnsRxns


AP MULTIPLE CHOICE PROBLEMSC 69. What is the final concentration of barium ions, [Ba2+], in

solution when 100. mL of 0.10 M BaCl2(aq) is mixed with 100. mL of 0.050 M H2SO4(aq)? A) 0.00 MB) 0.012 MC) 0.025 MD) 0.075 ME) 0.10 M

1999

04

04/05

TEST

SolnsRxns

A 70. When 100 mL of 1.0 M Na3PO4 is mixed with 100 mL of 1.0 M AgNO3, a yellow precipitate forms and [Ag+] becomes negligibly small. Which of the following is a correct listing of the ions remaining in solution in order of increasing concentration? A) [PO43¯] < [NO3¯] < [Na+]B) [PO43¯] < [Na+]<[NO3¯]C) [NO3¯] < [PO43¯] < [Na+]D) [Na+] < [NO3¯] < [PO43¯]E) [Na+] < [PO43¯] < [NO3¯]

1999

04

04/05

TEST

SolnsRxns

E 71. In a qualitative ananlysis for the presence of Pb2+, Fe2+, and Cu2+ ions in a aqueous solution, which of the following will allow the separation of Pb2+ from the other ions at room temperature? A) Adding dilute Na2S(aq) solutionB) Adding dilute HCl(aq) solutionC) Adding dilute NaOH(aq) solutionD) Adding dilute NH3(aq) solutionE) Adding dilute HNO3(aq) solution

1999

04

04/05

TEST

SolnsPreci

p

D 73. The volume of distilled water that should be added to 10.0 mL of 6.00 M HCl(aq) in order to prepare a 0.500 M HCl(aq) solution is approximately A) 50.0 mLB) 60.0 mLC) 100. mLD) 110. mLE) 120. mL

1999

04

04/05

TEST

SolnsMixin

g

B 21. When a sample of oxygen gas in a closed container of constant volume is heated until its absolute temperature is doubled, which of the following is also doubled?(A) The density of the gas(B) The pressure of the gas(C) The average velocity of the gas molecules(D) The number of molecules per cm3

(E) The potential energy of the molecules

1984

05 Gas


AP MULTIPLE CHOICE PROBLEMSB 23. The density of an unknown gas is 4.20 grams per liter at 3.00

atmospheres pressure and 127 °C. What is the molecular weight of this gas? (R = 0.0821 liter-atm / mole-K)(A) 14.6(B) 46.0(C) 88.0(D) 94.1(E) 138

1984

05 Gas

C 39. Equal masses of three different ideal Gas, X, Y, and Z, are mixed in a sealed rigid container. If the temperature of the system remains constant, which of the following statements about the partial pressure of gas X is correct?(A) It is equal to 1/3 the total pressure(B) It depends on the intermolecular forces of attraction between molecules of X, Y, and Z.(C) It depends on the relative molecular masses of X, Y, and Z.(D) It depends on the average distance traveled between molecular collisions.(E) It can be calculated with knowledge only of the volume of the container.

1984

05 Gas

E 50. Two flexible containers for Gas are at the same temperature and pressure. One holds 0.50 gram of hydrogen and the other holds 8.0 grams of oxygen. Which of the following statements regarding these gas samples is FALSE?(A) The volume of the hydrogen container is the same as the volume of the oxygen container.(B) The number of molecules in the hydrogen container is the same as the number of molecules in the oxygen container.(C) The density of the hydrogen sample is less than that of the oxygen sample.(D) The average kinetic energy of the hydrogen molecules is the same as the average kinetic energy of the oxygen molecules.(E) The average speed of the hydrogen molecules is the same as the average speed of the oxygen molecules.

1984

05 Gas

A 52. 3 Ag(s) + 4 HNO3 <===> 3 AgNO3 + NO(g) + 2 H2OThe reaction of silver metal and dilute nitric acid proceeds according to the equation above. If 0.10 mole of powdered silver is added to 10. milliliters of 6.0-molar nitric acid, the number of moles of NO gas that can be formed is (A) 0.015 mole(B) 0.020 mole(C) 0.030 mole(D) 0.045 mole(E) 0.090 mole

1984

05 Gas


AP MULTIPLE CHOICE PROBLEMSC 72. A compound is heated to produce a gas whose molecular

weight is to be determined. The gas is collected by displacing water in a water-filled flask inverted in a trough of water. Which of the following is necessary to calculate the molecular weight of the gas, but does NOT need to be measured during the experiment?(A) Mass of the compound used in the experiment(B) Temperature of the water in the trough(C) Vapor pressure of the water(D) Barometric pressure(E) Volume of water displaced from the flask

1984

05 Gas

A 78. When the actual gas volume is greater then the volume predicted by the ideal gas law, the explanation lies in the fact that the ideal gas law does NOT include a factor for molecular.(A) volume(B) mass(C) velocity(D) attractions(E) shape

1984

05 Gas

B 85. A sample of 9.00 grams of aluminum metal is added to an excess of hydrochloric acid. The volume of hydrogen gas produced at standard temperature and pressure is(A) 22.4 liters(B) 11.2 liters(C) 7.46 liters(D) 5.60 liters(E) 3.74 liters

1984

05 Gas

C 16. A gaseous mixture containing 7.0 moles of nitrogen, 2.5 moles of oxygen, and 0.50 mole of helium exerts a total pressure of 0.90 atmosphere. What is the partial pressure of the nitrogen?(A) 0.13 atm(B) 0.27 atm(C) 0.63 atm(D) 0.90 atm(E) 6.3 atm

1989

0506

TEST

Gas

B 24. A sample of 0.010 mole of oxygen gas is confined at 127 °C and 0.80 atmosphere. What would be the pressure of this sample at 27 °C and the same volume?(A) 0.10 atm(B) 0.20 atm(C) 0.60 atm(D) 0.80 atm(E) 1.1 atm

1989

05 Gas


AP MULTIPLE CHOICE PROBLEMSB 30. Hydrogen gas is collected over water at 24 °C. The total

pressure of the sample is 755 millimeters of mercury. At 24 °C, the vapor pressure of water is 22 millimeters of mercury. What is the partial pressure of the hydrogen gas?(A) 22 mm Hg(B) 733 mm Hg(C) 755 mm Hg(D) 760 mm Hg(E) 777 mm Hg

1989

0506

TEST

Gas

C 32. A 2.00-liter sample of nitrogen gas at 27 °C and 600. millimeters of mercury is heated until it occupies a volume of 5.00 liters. If the pressure remains unchanged, the final temperature of the gas is(A) 68 °C(B) 120 °C(C) 477 °C(D) 677 °C(E) 950. °C

1989

0506

TEST

Gas

B 40. 2 K + 2 H2O ---> 2 K+ + 2 OH¯ + H2 When 0.400 mole of potassium reacts with excess water at standard temperature and pressure as shown in the equation above, the volume of hydrogen gas produced is(A) 1.12 liters(B) 2.24 liters(C) 3.36 liters(D) 4.48 liters(E) 6.72 liters

1989

0504/0

5 TES

T Gas

C 62. As the temperature is raised from 20 ° C to 40 ° C, the average kinetic energy of neon atoms changes by a factor of(A) 1/2(B) [square root of](313/293)(C) 313/293(D) 2(E) 4

1989

0506

TEST

Gas

C 24. A sample of 0.0100 mole of oxygen gas is confined at 37° C and 0.216 atmosphere. What would be the pressure of this sample at 15° C and the same volume?(A) 0.0876 atm(B) 0.175 atm(C) 0.201 atm(D) 0.233 atm(E) 0.533 atm

1994 05

04/05

TEST

Gas


AP MULTIPLE CHOICE PROBLEMSC 33. A hydrocarbon gas with an empirical formula CH2 has a density

of 1.88 grams per liter at 0 °C and 1.00 atmosphere. A possible formula for the hydrocarbon is(A) CH2(B) C2H4(C) C3H6(D) C4H8(E) C5H10

1994

0504/0

5 TES

T Gas

D 37R. A sample of 3.0 grams of an ideal gas at 121 °C and 1.0 atmosphere pressure has a volume of 1.0 Iiters. Which of the following expressions is correct for the molar mass of the gas? The ideal gas constant, R, is 0.08 (L-atm) / (mole K).(A) [(0.08)(400)] / [(3.0)(1.0)(1.5)](B) [(l.O)(l.5)] / [(3.0)(0.08)(400)](C) [(O.O8)(1.0)(1.5)] / [(3.0)(400)](D) [(3.0)(0.08)(400)] / [(1.0)(1.5)](E) [(3.0)(0.08)(1.5)] / (1.0)(400)]

1994

0504/0

5 TES

T Gas

C 39. Samples of F2 gas and Xe gas are mixed in a container of fixed volume. The initial partial pressure of the F2 gas is 8.0 atmospheres and that of the Xe gas is 1.7 atmospheres. When all of the Xe gas reacted, forming a solid compound, the pressure of the unreacted F2 gas was 4.6 atmospheres. The temperature remained constant. What is the formula of the compound?(A) XeF(B) XeF3(C) XeF4(D) XeF6(E) XeF8

1994

0506

TEST

Gas

C 40. The system shown above is at equilibrium at 28 °C. At this temperature, the vapor pressure of water is 28 millimeters of mercury. The partial pressure of O2(g) in the system is(A) 28 mm Hg(B) 56 mm Hg(C) 133 mm Hg(D) 161 mm Hg(E) 189 mm Hg

1994

0504/0

5 TES

T Gas


AP MULTIPLE CHOICE PROBLEMSC 45. A sample of an ideal gas is cooled from 50.0 °C to 25.0 °C in a

sealed container of constant volume. Which of the following values for the gas will decrease?I. The average molecular mass of the gasII. The average distance between the moleculesIII. The average speed of the molecules(A) I only(B) II only(C) III only(D) I and III(E) II and III

1994

05

04/05

TEST

Gas

D 64. At 25 °C, a sample of NH3 (molar mass 17 grams) effuses at the rate of 0.050 mole per minute. Under the same conditions, which of the following Gas effuses at approximately one-half that rate?(A) O2 (molar mass 32 grams)(B) He2 (molar mass 4.0 grams)(C) CO2 (molar mass 44 grams)(D) Cl2 (molar mass 71 grams)(E) CH4 (molar mass 16 grams)

1994

0504/0

5 TES

T Gas

B 52. Under which of the following sets of conditions could the most O2(g) be dissolved in H2O(l)? 1

999

05Gas

E 23. A hot-air balloon, shown right, rises. Which of the following is the best explanation for this observation? (A) The pressure on the walls of the balloon increases with increasing tempearature.(B) The difference in temperature between the air inside and outside the ballon produces convection currents.(C) The cooler air outside the balloon pushes in on the walls of the ballon.(D) The rate of diffusion of cooler air is less than that of warmer air.(E) The air density inside the ballon is less than that of the surrounding air.

1999

05Gas


Pressure of O2(g)Above H2O(l) (atm)

Temperature of H2O(l) °(C)

A) 5.0 80 B) 5.0 20 C) 1.0 80 D) 1.0 20 E) 0.5 20

AP MULTIPLE CHOICE PROBLEMSC 44. A rigid metal tank contains oxygen gas. Which of the following

applies to the gas in the tank when additional oxygen is added at constant temperature? (A) The volume of the gas increase.(B) The pressure of the gas decreases.(C) The average speed of the gas molecules remains th same.(D) The total number of gas molecules remains the same.(E) The average distance between the gas molecules increases.

1999

05

04/05

TEST

Gas

A 53. W(g) + X(g) --> Y(g) + Z(g) Gas W and X react in a closed, rigid vessel to form Gas Y and Z according to the equation above. The initial pressure of W(g) is 1.20 atm and that of X(g) is 1.60 atm. No Y(g) or Z(g) is initially present. The experiment is carried out at constant temperature. What is the partial pressure of Z(g) when the partial pressure of W(g) has decreased to 1.0 atm? A) 0.20 atmB) 0.40 atmC) 1.0 atmD) 1.2 atmE) 1.4 atm

1999

05

04/05

TEST

Gas

A60. NH4NO3(s) --> N2O(g) + 2 H2O(g) A 0.03 mol sample of NH4NO3(s) decomposes completely according to the balanced equation above. The total pressure in the flask measured at 400 K is closest to which of the following? ( The value of the gas constant,R, is 0.082 L atm mol¯1 K¯1) (A) 3 atm(B) 1 atm(C) 0.5 atm(D) 0.1 atm(E) 0.03 atm

1999

05

04/05

TEST

Gas

A 64. Equal numbers of moles of He(g), Ar(g), and Ne(g) are placed in a glass vessel at room temperature. If the vessel has a pinhole-sized leak, which of the following will be true regarding the relative values of the partial pressures of the Gas remaining in the vessel after some of the gas mixture has effused? A) PHe < PNe < PArB) PHe < PAr < PNeC) PNe < PAr < PHeD) PAr < PHe < PNeE) PHe = PAr = PNe

1999

05

04/05

TEST

Gas

A 74. Which of the following Gas deviates most from ideal behavior? A) SO2B) NeC) CH4D) N2E) H2

1999

05

06 TES

TGas


AP MULTIPLE CHOICE PROBLEMSC 47. CH4(g) + 2 O2(g) ---> CO2(g) + 2 H2O(l); = - 889.1 kJ

Hf° H2O(l) = - 285.8 kJ / moleHf° CO2(g) = - 393.3 kJ / moleWhat is the standard heat of formation of methane, Hf° CH4(g), as calculated from the data above?(A) -210.0 kJ/mole(B) -107.5 kJ/mole(C) -75.8 kJ/mole(D) 75.8 kJ/mole(E) 210.0 kJ/mole

1984

06

06 TES

T Ther

m

A 48.Which of the following is a graph that describes the pathway of reaction that is endothermic and has high activation energy?

A B C

D E

1989

06

06 TES

T Ther

m

D 25R.H2(g) + 1/2 O2(g) ---> H2O(l) H° = x 2 Na(s) + 1/2 O2(g) ---> Na2O(s) H° = y Na(s) + 1/2 O2(g) + 1/2 H2(g) ---> NaOH(s) H° = z Based on the information above, what is the standard enthalpy change for the following reaction?Na2O(s) + H2O(l) ---> 2 NaOH(s)(A) x + y + z(B) x + y - z(C) x + y - 2z(D) 2z - x - y(E) z - x - y

1994

06

06 TES

T Ther

m


AP MULTIPLE CHOICE PROBLEMSD 30. The energy diagram for

the reaction X + Y ---> Z is shown above. The addition of a catalyst to this reaction would cause a change in which of the indicated energy differences?(A) I only(B) II only(C) III only(D) I and II only(E) I, II, and III

1994

06

06 TES

T Ther

m

C 19. Which of the following best describes the role of the spark from the spark plug in an automobile engine? (A) The spark decreases the energy of activation for the slow step.(B) The spark increases the concentration of the volatile reactant.(C) The spark supplies some of the energy of activation for the combustion reaction.(D) The spark provides a more favorable activated complex for the combustion reaction.(E) The spark provides the heat of vaporization for the volatile hydrocarbon.

1999

06

06 TES

T Ther

m

E61. C2H4(g) + 3 O2(g) --> 2 CO2(g) + 2 H2O(g) For the reaction of ethylene represented above, H is - 1,323 kJ. What is the value of H if the combustion produced liquid water H2O (l), rather than water vapor H2O(g)? (H for the phase change H2O(g) --> H2O(l) is -44 kJ mol¯1.) A) -1,235 kJB) -1,279 kJC) -1,323 kJD) -1,367 kJE) -1,411 kJ

1999

06

06 TES

TTher

m

E 22. 1s2 2s22p6 3s23p3 Atoms of an element, X, have the electronic configuration shown above. The compound most likely formed with magnesium, Mg, is (A) MgX(B) Mg2X(C) MgX2(D) MgX3(E) Mg3X2

1984

07

07 TES

T Atom

ic


AP MULTIPLE CHOICE PROBLEMSE 43. The elements in which of the following have most nearly the

same atomic radius?(A) Be, B, C, N(B) Ne, Ar, Kr, Xe(C) Mg, Ca, Sr, Ba(D) C, P, Se, I(E) Cr, Mn, Fe, Co

1984

07

07 TES

T Atom

ic

A 58. Which of the following represents the ground state electron configuration for the Mn3+ ion? (Atomic number Mn = 25)(A) 1s2 2s22p6 3s23p63d4

(B) 1s2 2s22p6 3s23p63d5 4s2

(C) 1s2 2s22p6 3s23p63d2 4s2

(D) 1s2 2s22p6 3s23p63d8 4s2

(E) 1s2 2s22p6 3s23p63d3 4s1

1984

07

07 TES

T Atom

ic

D 66. Ca, V, Co, Zn, AsGaseous atoms of which of the elements above are paramagnetic?(A) Ca and As only(B) Zn and As only(C) Ca, V, and Co only(D) V, Co, and As only(E) V, Co, and Zn only

1984

07

07 TES

T Atom

ic

E 70. One of the outermost electrons in a strontium atom in the ground state can be described by which of the following sets of four quantum numbers?(A) 5, 2, 0, 1/2(B) 5, 1, 1, 1/2(C) 5, 1, 0, 1/2(D) 5, 0, 1, 1/2(E) 5, 0, 0, 1/2

1984

07

07 TES

T Atom

ic

BEB

Use the following answers for questions 1 - 3.(A) F(B) S(C) Mg(D) Ar(E) Mn 1. Forms monatomic ions with 2¯ charge in solutions2. Forms a compound having the formula KXO43. Forms oxides that are common air pollutants and that yield acidic solution in water

1984

07 Basics


AP MULTIPLE CHOICE PROBLEMSAED

1. Use these answers for questions 1 - 3.(A) O(B) La(C) Rb(D) Mg(E) N 1. What is the most electronegative element of the above?2. Which element exhibits the greatest number of different oxidation states?3. Which of the elements above has the smallest ionic radius for its most commonly found ion?

1989

07

07 TES

T Atom

ic

A 33. Which of the following conclusions can be drawn from J. J. Thomson's cathode ray experiments?(A) Atoms contain electrons.(B) Practically all the mass of an atom is contained in its nucleus.(C) Atoms contain protons, neutrons, and electrons.(D) Atoms have a positively charged nucleus surrounded by an electron cloud.(E) No two electrons in one atom can have the same four quantum numbers.

1989

07 Atomic

CEBB

4. Use these answers for questions 4 - 7.(A) 1s2 2s22p5 3s23p5

(B) 1s2 2s22p6 3s23p6

(C) 1s2 2s22p62d10 3s23p6

(D) 1s2 2s22p6 3s23p63d5

(E) 1s2 2s22p6 3s23p63d3 4s2 4. An impossible electronic configuration5. The ground-state configuration for the atoms of a transition element6. The ground-state configuration of a negative ion of a halogen7. The ground-state configuration of a common ion of an alkaline earth element

1989

07

07 TES

T Atom

ic

CEBA

1. Questions 1-4 (A) Heisenberg uncertainty principle(B) Pauli exclusion principle(C) Hund's rule (principle of maximum multiplicity)(D) Shielding effect(E) Wave nature of matter 1. Can be used to predict that a gaseous carbon atom in its ground state is paramagnetic2. Explains the experimental phenomenon of electron diffraction3. Indicates that an atomic orbital can hold no more than two electrons4. Predicts that it is impossible to determine simultaneously the exact position and the exact velocity of an electron

1994

07 Atomic


AP MULTIPLE CHOICE PROBLEMSC 27. Which of the following sets of quantum numbers (n, l, ml, ms)

best describes the valence electron of highest energy in a ground-state gallium atom (atomic number 31) ?(A) 4, 0, 0, 1/2(B) 4, 0, 1, 1/2(C) 4, 1, 1, 1/2(D) 4, 1, 2, 1/2(E) 4, 2, 0, 1/2

1994

07 Atomic

D 54. All of the following statements concerning the characteristics of the halogens are true EXCEPT: (A) The first ionization energies (potentials) decrease as the atomic numbers of the halogens increase.(B) Fluorine is the best oxidizing agent.(C) Fluorine atoms have the smallest radii.(D) Iodine liberates free bromine from a solution of bromide ion.(E) Fluorine is the most electronegative of the halogens.

1994

07

07 TES

T Atom

ic

DACE

5. Question 5-8 refer to atoms for which the occupied atomic orbitals shown below. 5. Represents an atom that is chemically unreactive 6. Represents an atom in an excited state 7. Represents an atom that has four valence electrons. 8. Represents an atom of a transition metal.

1999

07

07 TES

T Atom

ic

D 50. In the periodic table, as the atomic number increases from 11 to 17, what happens to the atomic radius? (A) It remains constant.(B) It increases only.(C) It increases, then decreases.(D) It decreases only.(E) It decreases, then increases.

1999

07 Atomic

E 51. Which of the following is a correct interpretation of the results of Rutherford's experiments in which gold atoms were bombarded with alpha particles? (A) Atoms have equal numbers of positive and negative charges.(B) Electrons in atoms are arranged in shells.(C) Neutrons are at the center of an atom.(D) Neutrons and protons in atoms have nearly equal mass.(E) The positive charge of an atom is concentrated in a small region.

1999

07

07 TES

T Atom

ic


AP MULTIPLE CHOICE PROBLEMS

C

37. The ionization energies for element X are listed in the table above. On the basis of the data, element X is most likely to be (A) Na(B) Mg(C) AI(D) Si(E) P

1999

07

07 TES

T Atom

ic

A 41. Which of the following molecules has the shortest bond length?(A) N2(B) O2(C) Cl2(D) Br2(E) I2

1984

080910

Bonds

E 51. Pi bonding occurs in each of the following species EXCEPT(A) CO2(B) C2H4(C) CN¯(D) C6H6(E) CH4

1984

080910

Bonds

E 60. Which of the following has a zero dipole moment?(A) HCN(B) NH3(C) SO2(D) NO2(E) PF5

1984

080910

Bonds

CA

8. Use the following answers for questions 8 - 9.(A) A network solid with covalent bonding(B) A molecular solid with zero dipole moment(C) A molecular solid with hydrogen bonding(D) An ionic solid(E) A metallic solid 8. Solid ethyl alcohol, C2H5OH9. Silicon dioxide, SiO2

1984

080910

Bonds

B 80. For which of the following molecules are resonance structures necessary to describe the bonding satisfactorily?(A) H2S(B) SO2(C) CO2(D) OF2(E) PF3

1984

080910

Bonds


Ionization Energies for element X (kJ mol¯1)

First Second Third Fourth Five580 1815 2740 11600 14800

AP MULTIPLE CHOICE PROBLEMSE 18. The liquefied hydrogen halides have

the normal boiling points given below. The relatively high boiling point of HF can be correctly explained by which of the followng?(A) HF gas is more ideal.(B) HF is the strongest acid.(C) HF molecules have a smaller dipole moment.(D) HF is much less soluble in water.(E) HF molecules tend to form hydrogen bonds.

1984

080910

Bonds

EABD

11. Use these answers for questions 11 - 14.(A) hydrogen bonding(B) hybridization(C) ionic bonding(D) resonance(E) van der Waals forces (London dispersion forces) 11. Is used to explain why iodine molecules are held together in the solid state12. Is used to explain why the boiling point of HF is greater than the boiling point of HBr13. Is used to explain the fact that the four bonds in methane are equivalent14. Is used to explain the fact that the carbon-to-carbon bonds in benzene, C6H6, are identical

1989

080910

Bonds

C 17. The Lewis dot structure of which of the following molecules shows only one unshared pair of valence electron?(A) Cl2(B) N2(C) NH3(D) CCl4(E) H2O2

1989

080910

Bonds

A 31. The structural isomers C2H5OH and CH3OCH3 would be expected to have the same values for which of the following? (Assume ideal behavior.)(A) Gaseous densities at the same temperature and pressure(B) Vapor pressures at the same temperature(C) Boiling points(D) Melting points(E) Heats of vaporization

1989

080910

Bonds

D 42. The SbCl5 molecule has trigonal bipyramid structure. Therefore, the hybridization of Sb orbitals should be(A) sp2

(B) sp3

(C) dsp2

(D) dsp3

(E) d2sp3

1989

080910

Bonds


Hydrogen Halide

Normal Boiling Point,

°CHF +19HCl - 85HBr - 67HI - 35

AP MULTIPLE CHOICE PROBLEMSC 47. CCl4, CO2, PCl3, PCl5, SF6 Which of the following does not

describe any of the molecules above?(A) Linear(B) Octahedral(C) Square planar(D) Tetrahedral(E) Trigonal pyramidal

1989

080910

Bonds

E 59. Which of the following compounds is ionic and contains both sigma and pi covalent bonds?(A) Fe(OH)3(B) HClO(C) H2S(D) NO2(E) NaCN

1989

080910

Bonds

E 15. In a molecule in which the central atom exhibits sp3d2 hybrid orbitals, the electron pairs are directed toward the corners of(A) a tetrahedron(B) a square-based pyramid(C) a trigonal bipyramid(D) a square(E) an octahedron

1994

080910

Bonds

D 32. CH3CH2OH boils at 78 °C and CH3OCH3 boils at - 24 °C, although both compounds have the same composition. This difference in boiling points may be attributed to a difference in(A) molecular mass(B) density(C) specific heat(D) hydrogen bonding(E) heat of combustion

1994

080910

Bonds

E 34.X = CH3-CH2-CH2-CH2-CH3Y = CH3-CH2-CH2-CH2-OHZ = HO-CH2-CH2-CH2-OHBased on concepts of polarity and hydrogen bonding, which of the following sequences correctly lists the compounds above in the order of their increasing solubility in water?(A) Z < Y < X(B) Y < Z < X(C) Y < X < Z(D) X < Z < Y(E) X < Y < Z

1994

080910

Bonds


AP MULTIPLE CHOICE PROBLEMSA 57. Molecules that have planar configurations include which of the

following?I. BCl3II. CHCl3III. NCl3(A) I only(B) III only(C) I and II only(D) II and III only(E) I, II, and III

1994

080910

Bonds

A 62. The electron-dot structure (Lewis structure) for which of the following molecules would have two unshared pairs of electrons on the central atom?(A) H2S(B) NH3(C) CH4(D) HCN(E) CO2

1994

080910

Bonds

A 68. Which of the following molecules has a dipole moment of zero?(A) C6H6 (benzene)(B) NO(C) SO2(D) NH3(E) H2S

1994

080910

Bonds

CDC

8. Questions 8-10 refer to the following diatomic species.(A) Li2(B) B2(C) N2(D) O2(E) F2 8. Has the largest bond-dissociation energy9. Has a bond order of 210. Contains 1 sigma (s) and 2 pi (p) bonds

1994

080910

Bonds

B 60. R. I2(g) + 3 Cl2(g) ---> 2 ICl3(g)According to the data in the table below, what is the value of H° for the reaction represented above?(A) - 870 kJ(B) - 390 kJ(C) + 180 kJ(D) + 450 kJ(E) + 1,260 kJ

1994

080910

BondThermo


Bond Average Bond Energy (kj/mole)

I---I 150 Cl---Cl 240 I---Cl 210

AP MULTIPLE CHOICE PROBLEMSB 28. The melting point of MgO is higher than that of NaF.

Explanations for this observation include which of the following? I. Mg2+ is more positively charged than Na+

II. O2¯ is more negatively charged than F¯III. The O2¯ ion is smaller than the F¯ ion (A) II only(B) I and II only(C) I and III only(D) II and III only(E) I, II, and III

1999

080910

Bonds

D 32. Types of hybridization exhibited by the C atoms in propene, CH3CHCH2, include which of the following? I. spII. sp2

III. sp3 (A) I only(B) III only(C) I and II only(D) II and III only(E) I, II, and III

1999

080910

Org.Bond

s

D 40. Of the following molecules, which has the largest dipole moment? (A) CO(B) CO2(C) O2(D) HF(E) F2

1999

080910

Bonds

C 58. On a mountaintop, it is observed that water boils at 90°C, not at 100°C as at sea level. This phenomenon occurs because on the mountaintop the A) equilibrium water vapor pressure is higher due to the higher atmospheric pressureB) equilibrium water vapor pressure is lower due to the higher atmospheric pressureC) equilibrium water vapor pressure equals the atmospheric pressure at a lower temperatureD) water molecules have a higher average kinetic energy due to the lower atmospheric pressureE) water contains a greater concentration of dissolved Gas

1999

080910

Liquids

C 68. In which of the following processes are covalent bonds broken? A) I2(s) --> I2(g)B) CO2(s) --> CO2(g)C) NaCl(s) --> NaCl(l)D) C(diamond) --> C(g)E) Fe(s) --> Fe(l)

1999

080910

Bonds


AP MULTIPLE CHOICE PROBLEMSD 19. Which of the following

represents a pair of isotopes?

1984

123

06 & 07

TEST

Basics

A 24. The formula for potassium hexacyanoferrate(II) is (A) K4[Fe(CN)6](B) K3[Fe(CN)6](C) K2[Pt(CN)4](D) K2[Pt(CN)6](E) KCN

1984

123

Misc.

D 44. What number of moles of O2 is needed to produce 14.2 grams of P4O10 from P? (Molecular weight P4O10 = 284)(A) 0.0500 mole(B) 0.0625 mole(C) 0.125 mole(D) 0.250 mole(E) 0.500 mole

1984

123

01-03

TEST

Stoich

D 73. A 27.0-gram sample of an unknown hydrocarbon was burned in excess oxygen to form 88.0 grams of carbon dioxide and 27.0 grams of water. What is a possible molecular formula of the hydrocarbon?(A) CH4(B) C2H2(C) C4H3(D) C4H6(E) C4H10

1984

123

01-03

TEST

RxnsStoic

h

E 23. How many grams of calcium nitrate, Ca(NO3)2, contains 24 grams of oxygen atoms?(A) 164 grams(B) 96 grams(C) 62 grams(D) 50. grams(E) 41 grams

1989

123

01-03

TEST

Stoich


Atomic Number

Mass Number

(A) I.II.

67

1414

(B) I.II.

614

714

(C) I.II.

614

1428

(D) I.II.

77

1314

(E) I.II.

816

1620

AP MULTIPLE CHOICE PROBLEMSD 25. The simplest formula for an oxide of nitrogen that is 36.8

percent nitrogen by weight is(A) N2O(B) NO(C) NO2(D) N2O3(E) N2O5

1989

123

Stoich

B 39. When a hydrate of Na2CO3 is heated until all the water is removed, it loses 54.3 percent of its mass. The formula of the hydrate is(A) Na2CO3 . 10 H2O(B) Na2CO3 . 7 H2O(C) Na2CO3 . 5 H2O(D) Na2CO3 . 3 H2O(E) Na2CO3 . H2O

1989

123

Stoich

D 45. A measured mass of an unreactive metal was dropped into a small graduated cylinder half filled with water. The following measurements were made.Mass of metal = 19.611 gramsVolume of water before addition of metal = 12.4 millilitersVolume of water after addition of metal = 14.9 milliliters The density of the metal should be reported as(A) 7.8444 grams per mL(B) 7.844 grams per mL(C) 7.84 grams per mL(D) 7.8 grams per mL(E) 8 grams per mL

1989

123

Genl Info

B 19R. In which of the following compounds is the mass ratio of chromium to oxygen closest to 1.6 to 1.0?(A) CrO3(B) CrO2(C) CrO(D) Cr20(E) Cr2O3

1994

123

06 TES

TStoic

h

D 42.Mass of an empty container = 3.0 gramsMass of the container plus the solid sample = 25.0 gramsVolume of the solid sample = 11.0 cubic centimetersThe data above were gathered in order to determine the density of an unknown solid. The density of the sample should be reported as(A) 0.5 g/cm3

(B) 0.50 g/cm3

(C) 2.0 g/cm3

(D) 2.00 g/cm3

(E) 2.27 g/cm3

1994

123

01-03

TEST

Genl Info


AP MULTIPLE CHOICE PROBLEMSC 47. When hafnium metal is heated in an atmosphere of chlorine

gas, the product of the reaction is found to contain 62.2 percent Hf by mass and 37.4 percent Cl by mass. What is the empirical formula for this compound? (A) HfCl(B) HfCl2(C) HfCl3(D) HfCl4(E) Hf2Cl3

1999

123

06 TES

TStoic

h

E 49. Which of the following techniques is most appropriate for the recovery of solid KNO3 from an aqueous solution of KNO3? (A) Paper chromatography(B) Filtration(C) Titration(D) Electrolysis(E) Evaporation to dryness

1999

123

Lab

E 27. The critical temperature of a substance is the(A) temperature at which the vapor pressure of the liquid is equal to the external pressure(B) temperature at which the vapor pressure of the liquid is equal to 760 mm Hg(C) temperature at which the solid, liquid, and vapor phases are all in equilibrium(D) Temperature at which liquid and vapor phases are in equilibrium at I atmosphere(E) lowest temperature above which a substance cnnot be liquified at any applied pressure

1984

10 L&S

A 54. Which of the following statements is always true about the phase diagram of any one-component system?(A) The slope of the curve representing equilibrium between the vapor and liquid phases is positive.(B) The slope of the curve representing equilibrium between the liquid and solid phases is negative.(C) The slope of the curve representing equilibrium between the liquid and solid phases is positive.(D) the temperature at the triple point is greater than the normal freezing point.(E) The pressure at the triple point is greater than 1 atmosphere.

1984

10 L&S


AP MULTIPLE CHOICE PROBLEMSA 21. Which of the following is true at the triple point of a pure

substance?(A) The vapor pressure of the solid phase always equal the vapor pressure of the liquid phase.(B) The temperature is always 0.01 K lower that the normal melting point.(C) The liquid and gas phases of the substance always have the same density and are therefore indistinguishable.(D) the solid phase always melts if the pressure increases at constant temperature.(E) The liquid phase always vaporizes if the pressure increases at constant temperature.

1989

10 L&S

CBD

49. Use the following diagram for 49-51.49. The normal boiling point of the substanced represented by the phase diagram above is(A) -15 °C(B) -10 °C(C) 140 °C (D) greater than 140 °C(E) not determinable from the diagram 50. The phase diagram above provides sufficient information for determining the(A) Entrop. change on vaporization(B) conditions necessary for sublimation(C) deviations from ideal gas behavior of the gas phase(D) latent heat of vaporization(E) latent heat of fusion

51. For the substance represented in the diagram, which of the phases is most dense and which is least dense at - 15 °C.

1989

10 L&S


Most Dense Least Dense (A) Solid Gas (B) Solid Liquid (C) Liquid Solid (D) Liquid Gas

(E) The diagram gives no information about densities.

AP MULTIPLE CHOICE PROBLEMSC 26. Which of the following actions would be likely to change the

boiling point of a sample of a pure liquid in an open container?I. Placing it in a smaller containerII. Increasing the number of moles of the liquid in the containerIII. Moving the container and liquid to a higher altitude(A) I only(B) II only(C) III only(D) II and III only(E) I, II, and III

1994

10 L&S

ABB

5. Questions 5-7 refer to the phase diagram below of a pure substance.(A) Sublimation(B) Condensation(C) Solvation(D) Fusion(E) Freezing 5. If the temperature increases from 10° C to 60° C at a constant pressure of 0.4 atmosphcre, which of the processes occurs?6. If the temperature decreases from 110° C to 40° C at a constant pressure of 1.1 atmospheres, which of the processes occurs?7. If the pressure increases from 0.5 to 1.5 atmospheres at a constant temperature of 50° C, which of the processes occurs?

1994

10 L&S

ADC

13. Questions 13-16 refer to the following descriptions of bonding in different types of solids. (A) Lattice of positive and negative ions held together by electrostatic forces.(B) Closely packed lattice with delocalized electrons throughout(C) Strong single covalent bonds with weak intermolecular forces.(D) Strong multiple covalent bonds (including bonds.) with weak intermolecular forces(E) Macromolecules held together with strong polar bonds. 13. Cesium chloride, CsCl (s) 15. Carbon dioxide, CO2(s) 16. Methane, CH4(s)

1999

10 L&S

C 25. The cooling curve for a pure substance as it changes from a liquid to a solid is shown right. The solid and the liquid coexist at (A) point Q only(B) point R only(C) all points on the curve between Q and S(D) all points on the curve between R and T(E) no point on the curve

1999

10 L&S


AP MULTIPLE CHOICE PROBLEMSC 39. The phase diagram for a pure substance is

shown above. Which point on the diagram corresponds to the equilibrium between the solid and liquid phases at the normal melting point? (A) A(B) B(C) C(D) D(E) E

1999

10 L&S

BACD

10. Use the following answers for questions 10 - 13.(A) CO32¯(B) Cr2O72¯(C) NH4+

(D) Ba2+

(E) Al3+ Assume that you have an "unknown" consisting of an aqueous solution of a salt that contains one of the ions listed above. Which ions must be absent on the basis of each of the following observations of the "unknown"? 10. The solution is colorless11. The solution gives no apparent reaction with dilute hydrochloric acid.12. No odor can be detected when a sample of the solution is added drop by drop to a warm solution of sodium hydroxide.13. No precipitate is formed when a dilute solution of H2SO4 is added to a sample of the solution.

1984

11

SolnsPreci

p

Test 4

E 37. The molality of the glucose in a 1.0-molar glucose solution can be obtained by using which of the following?(A) Volume of the solution(B) Temperature of the solution(C) Solubility of glucose in water(D) Degree of dissociation of glucose(E) Density of the solution

1984

11

SolnsMolal

Test4

D 55. At 20. °C, the vapor pressure of toluene is 22 millimeters of mercury and that of benzene is 75 millimeters of mercury. An ideal solution, equimolar in toluene and benzene, is prepared. At 20. °C, what is the mole fraction of benzene in the vapor in equilibrium with this solution?(A) 0.23(B) 0.29(C) 0.50(D) 0.77(E) 0.83

1984

11Solns

Test4


AP MULTIPLE CHOICE PROBLEMSA 84. Which of the following aqueous solutions has the highest

boiling point?(A) 0.10 M potassium sulfate, K2SO4(B) 0.10 M hydrochloric acid, HCl(C) 0.10 M ammonium nitrate, NH4NO3(D) 0.10 M magnesium sulfalte, MgSO4(E) 0.20 M sucrose, C12H22O11

1984

11

SolnsColli

g

AP set 4

C 27. I. Difference in temperature between freezing point of solvent and freezing point of solvent and freezing point of solutionII. Molal freezing point depression constant, Kf, for solventIn addition to the information above, which of the following gives the minimum data required to determine the molecular mass of a nonionic substance by the freezing point depression technique?(A) No further information is necessary.(B) Mass of solute(C) Mass of solute and mass of solvent(D) Mass of solute and volume of solvent(E) Mass of solute, mass of solvent, and vapor pressure of solvent

1989

11 Lab

D 28. Which of the following is probably true for a solid solute with a highly endothermic heat of solution when dissolved in water?(A) The solid has a low lattice energy.(B) As the solute dissolves, the temperature of the solution increases.(C) The resulting solution is ideal.(D) The solid is more soluble at higher temperatures.(E) the solid has a high energy of hydration.

1989

11

Solns

Test 4

E 71. A solution of toluene (molecular weight 92.1) in benzene (molecular weight 78.1) is prepared. The mole fraction of toluene in the solution is 0.100. What is the molality of the solution?(A) 0.100 m(B) 0.703 m(C) 0.921 m(D) 1.28 m(E) 1.42 m

1989

11Solns

Test 4

C 14. Which of the following is lower for a 1.0-molar aqueous solution of any solute than it is for pure water?(A) pH(B) Vapor pressure(C) Freezing point(D) Electrical conductivity(E) Absorption of visible light

1994

11

SolnsColli

g

Test4


AP MULTIPLE CHOICE PROBLEMSE 44. Which of the following solutions has the lowest freezing point?

(A) 0.20 m C6H12O6, glucose(B) 0.20 m NH4Br(C) 0.20 m ZnSO4(D) 0.20 m KMnO4(E) 0.20 m MgCl2

1994

11

SolnsColli

g

Test4

C 31. If the temperature of an aqueous solution of NaCl is increased from 20 °C to 90 °C, which of the following statements is true? (A) The density of the solution remains unchanged.(B) The molarity of the solution remains unchanged.(C) The molality of the solution remains unchanged.(D) The mole fraction of solute decreases.(E) The mole fraction of solute increases.

1999

11Solns

Test4

D 43. A sample of 61.8 g of H3BO3, a weak acid is dissolved in 1,000 g of water to make a 1.0-molal solution. Which of the following would be the best procedure to determine to molarity of the solution? (Assume no additional information is available.) (A) Titration of the solution with standard acid(B) Measurement of the pH with a pH meter(C) Determination of the boiling point of the solution(D) Measurement of the total volume of the solution(E) Measurement of the specific heat of the solution

1999

11 Solns

A 75. Which of the following pairs of liquids forms the solution that is most ideal (most closely follows Raoult's law)? A) C8H18(l) and H2O(l)B) CH3CH2CH2OH(l) and H2O(l)C) CH3CH2CH2OH(l) and C8H18(l)D) C6H14(l) and C8H18(l)E) H2SO4(l) and H2O(l)

1999

11

Solns

Test4


AP MULTIPLE CHOICE PROBLEMSAA

25. Questions 25-26 H3AsO4 + 3I¯ + 2 H3O+ ---> H3AsO3 + I3¯ + H2OThe oxidation of iodide ions by arsenic acid in acidic aqueous solution occurs according to the stoichiometry shown above. The experimental rate law of the reaction is: Rate = k [H3AsO4] [I¯] [H3O+]25. What is the order of the reaction with respect to I¯?(A) 1(B) 2(C) 3(D) 5(E) 6 26. According to the rate law for the reaction, an increase in the concentration of hydronium ion has what effect on this reaction?(A) The rate of reaction increases.(B) The rate of reaction decreases.(C) The value of the equilibrium constant increases.(D) The value of the equilibrium constant decreases.(E) Neither the rate nor the value of the equilibrium constant is changed.

1984

12 Kinet.

C 28. 2 A(g) + B(g) <===> 2 C(g)When the concentration of substance B in the reaction above is doubled, all other factors being held constant, it is found that the rate of the reaction remains unchanged. The most probable explanation for this observation is that(A) the order of the reaction with respect to substance B is 1(B) substance B is not involved in any of the steps in the mechanism of the reaction(C) substance B is not involved in the rate-determining step of the mechanism, but is involved in subsequent steps(D) substance B is probably a catalyst, and as such, its effect on the rate of the reaction does not depend on its concentration(E) the reactant with the smallest coefficient in the balanced equation Genlly has little or no effecton the rate of the reaction

1984

12 Kinet.


AP MULTIPLE CHOICE PROBLEMSC 82. Nitramide, N2H2O2, decomposes slowly in aqueous solution.

This decomposition is believed to occur according to the reaction mechanism above. The rate law for the decomposition of nitramide that is consistent with this mechanism is given by which of the following?(A) Rate = k [N2H2O2](B) Rate = k [N2H2O2] [H+](C) Rate = (k [N2H2O2]) / [H+](D) Rate = (k [N2H2O2]) / [N2HO2¯](E) Rate = k [N2H2O2] [OH¯]

1984

12 Kinet.

B 57. rate = k[X] For the reaction whose rate law is given above, a plot of which of the following is a straight line?(A) [X] versus time(B) log [X] versus time(C) 1/[X] versus time(D) [X] versus 1/time(E) log [X] versus 1/time

1989

12 Kinet.

C 58. (CH3)3CCl(aq) + OH¯ ---> (CH3)3COH(aq) + Cl¯ For the reaction represented above, the experimental rate law is given as follows. Rate = k [(CH3)3CCl]If some solid sodium solid hydroxide is added to a solution that is 0.010-molar in (CH3)3CCl and 0.10-molar in NaOH, which of the following is true? (Assume the temperature and volume remain constant.) (A) Both the reaction rate and k increase.(B) Both the reaction rate and k decrease.(C) Both the reaction rate and k remain the same.(D) The reaction rate increases but k remains the same.(E) The reaction rate decreases but k remains the same.

1989

12 Kinet.

D 17. Relatively slow rates of chemical reaction are associated with which of the following?(A) The presence of a catalyst(B) High temperature(C) High concentration of reactants(D) Strong bonds in reactant molecules(E) Low activation energy

1994

12 Kinet.


Step 1) N2H2O2 <===> N2HO2¯ + H+

fast equilibrium

Step 2) N2HO2¯ ---> N2O + OH¯ (slow) Step 3) H+ + OH¯ ---> H2O (fast)

AP MULTIPLE CHOICE PROBLEMSB 23. The proposed steps for a catalyzed reaction between Ce4+ and

Tl+ are represented above. The products of the overall catalyzed reaction areStep 1: Ce4+ + Mn2+ ---> Ce3+ + Mn3+

Step 2: Ce4+ + Mn3+ ---> Ce3+ + Mn4+

Step 3: Mn4+ + Tl+ ---> Tl3+ + Mn2+

(A) Ce4+ and Tl+(B) Ce3+ and Tl3+

(C) Ce3+ and Mn3+

(D) Ce3+ and Mn4+

(E) Tl3+ and Mn2+

1994

12 Kinet.

B 49. The isomerization of cyclopropane to propylene is a first-order process with a half-life of 19 minutes at 500 °C. The time it takes for the partial pressure of cyclopropane to decrease from 1.0 atmosphere to 0.125 atmosphere at 500 °C is closest to(A) 38 minutes(B) 57 minutes(C) 76 minutes(D) 152 minutes(E) 190 minutes

1994

12 Kinet.

A 63. The graph above shows the results of a study of the reaction of X with a large excess of Y to yield Z. The concentrations of X and Y were measured over a period of time. According to the results, which of the following can be concluded about the rate of law for the reaction under the conditions studied? A) It is zero order in [X].B) It is first order in [X].C) It is second order in [X].D) It is the first order in [Y].E) The overall order of the reaction is 2.

1999

12 Kinet.

B 36. The initial-rate data in the table above were obtained for the reaction represented below. What is the experimental rate la for the reaction? (A) rate = k[NO] [O2](B) rate = k[NO] [O2]2

(C) rate = k[NO]2 [O2](D) rate = k[NO]2 [O2]2

(E) rate = k[NO] / [O2]

1999

12 Kinet.


Experiment

Initial [NO](mol L¯1

Initial [O2](mol L¯1

Initial Rate ofFormation of NO2(mol L¯1 s¯1)

1 0.10 0.10 2.5 x 10¯4 2 0.20 0.10 5.0 x 10¯4 3 0.20 0.40 8.0 x 10¯3

AP MULTIPLE CHOICE PROBLEMSC 36. CuO(s) + H2(g) <===> Cu(s) + H2O(g); H = - 2.0 kilojoules

When the substances in the equation above are at equilibrium at pressure P and temperature T, the equilibrium can be shifted to favor the products by(A) increasing the pressure by means of a moving piston at constant T(B) increasing the pressure by adding an inert gas such as nitrogen(C) decreasing the temperature(D) allowing some gases to escape at constant P and T(E) adding a catalyst

1984

13Tes

tEquil

.

B 57. For the reaction A(g) B(g) + C(g), the equilibrium constant, Kp, is 2 x 10¯4 at 25 °C. A mixture of the three gases at 25 °C is placed in a reaction flask and the initial pressures are PA = 2 atm, PB = 0.5 atm, and PC = 1 atm, At the instant of mixing, which of the following is true for the reaction as written? (A) G < 0(B) G > 0(C) S = 0(D) G° = 0(E) G° < 0

1984

13Tes

t

Equil.

Entrop.

B 76. HgO(s) + 4 I¯ + H2O HgI42¯ + 2 OH¯; H < 0 Consider the equilibrium above. Which of the following changes will increase the concentration of HgI42¯?(A) Increasing the concentration of OH¯(B) Adding 6 M HNO3(C) Increasing the mass of HgO present(D) Increasing the temperature(E) Adding a catalyst

1984

13Tes

tEquil

.

E 29. In which of the following systems would the number of moles of the substances present at equilibrium NOT be shifted by a change in the volume of the system at constant temperature?(A) CO(g) + NO(g) <===> CO2(g) + 1/2 N2(g)(B) N2(g) + 3 H2(g) <===> 2 NH3(g)(C) N2(g) + 2 O2(g) <===> 2 NO2(g)(D) N2O4(g) <===> 2 NO2(g)(E) NO(g) + O3(g) <===> NO2(g) + O2(g)

1989

13Tes

tEquil

.


AP MULTIPLE CHOICE PROBLEMSA 48. PCl3(g) + Cl2(g) PCl5(g) + energy

Some PCl3 and Cl2 are mixed in a container at 200 °C and the system reaches equilibrium according to the equation above. Which of the following causes an increase in the number of moles of PCl5 present at equilibrium?I. Decreasing the volume of the containerII. Raising the temperatureIII. Adding a mole of He gas at constant volume(A) I only(B) II only(C) I and III only(D) II and III only(E) I, II, and III

1994

13Tes

tEquil

.

D 51. 4 HCl(g) + O2(g) 2 Cl2(g) + 2 H2O(g) Equal numbers of moles of HCl and O2 in a closed system are allowed to reach equilibrium as represented by the equation above. Which of the following must be true at equilibrium?I. [HCl] must be less than [Cl2].II. [O2] must be greater than [HCl].III. [Cl2] must equal [H2O].(A) I only(B) II only(C) I and III only(D) II and III only(E) I, II, and III

1994

13Tes

tEquil

.

A 73 R. 2 SO2(g) + O2(g) 2 SO3(g) When 0.40 mole of SO3 and 0.60 mole of O2 are placed in an evacuated 1.00-liter flask, the reaction represented above occurs. After the reactants and the product reach equilibrium and the initial temperature is restored, the flask is found to contain 0.30 mole of S03. Based on these results, the expression for the equilibrium constant, Kc, of the reaction is(A) (0.30)2 / [(0.45)(0.10)2] (B) (0 30)2 / [(0.60)(0.40)2] (C) (2 x 0.30) / [(0.45)(2 x 0.10)] (D) (0.30) / [(0.45)(0.10)] (E) (0.30) / [(0.60)(0.40)]

1994

13Tes

tEquil

.

B

54. 2NO(g) + O2(g) 2 NO2(g) H < 0 Which of the following changes alone would cause a decrease in the value of Keq for the reaction represented above? A) Decreasing the temperatureB) Increasing the temperatureC) Decreasing the volume of the reaction vesselD) Increasing the volume of the reaction vesselE) Adding a catalyst

1999

13Tes

tEquil

.


AP MULTIPLE CHOICE PROBLEMSD 33. The pH of 0.1-molar ammonia is approximately

(A) 1(B) 4(C) 7(D) 11(E) 14

1984

14 Acid Base

E 48. Which of the following ions is the strongest Lewis acid?(A) Na+

(B) Cl¯(C) CH3COO¯(D) Mg2+

(E) Al3+

1984

14 Acid Base

C 49. Each of the following can act as both a Brönsted acid and a Brönsted base EXCEPT(A) HCO3¯(B) H2PO4¯(C) NH4+

(D) H2O(E) HS¯

1984

14 Acid Base

B 53. Which, if any, of the following species is in the greatest concentration in a 0.100-molar solution of H2SO4 in water?(A) H2SO4 molecules(B) H3O+ ions(C) HSO4¯ ions(D) SO42¯ ions(E) All species are in equilibrium and therefore have the same concentrations.

1984

14 Acid Base

E 71. Which of the following reactions does NOT proceed significantly to the right in aqueous solutions?(A) H3O+ + OH¯ ---> 2 H2O(B) HCN + OH¯ ---> H2O + CN¯(C) Cu(H2O)42+ + 4 NH3 ---> Cu(NH3)42+ + 4H2O(D) H2SO4 + H2O ---> H3O+ + HSO4¯(E) H2O + HSO4¯ ---> H2SO4 + OH¯

1984

14Aque

. Equil

.

E 75. If the acid dissociation constant, Ka, for an acid HA is 8 x 10¯4 at 25 °C, what percent of the acid is dissociated in a 0.50-molar solution of HA at 25 °C?(A) 0.08%(B) 0.2%(C) 1%(D) 2%(E) 4%

1984

14 Acid Base


AP MULTIPLE CHOICE PROBLEMSA 34. All of the following species can function as Brönsted-Lowry

bases in solution EXCEPT(A) H2O(B) NH3(C) S2¯(D) NH4+

(E) HCO3¯

1989

14 Acid Base

E 46. As the number of oxygen atoms increases in any series of oxygen acids, such as HXO, HXO2, HXO3, ...., which of the following is generally true?(A) The acid strength varies unpredictably.(B) The acid strength decreases only if X is a nonmetal.(C) The acid strength decreases only if X is a metal.(D) The acid strength decreases whether X is a nonmetal or a metal.(E) The acid strength increases.

1989

14 Acid Base

B 54. Which of the following is the correct equilibrium expression for the hydrolysis of CO32¯ ?(A) K = [HCO3¯ ] / ( [CO32¯ ] [H3O+] )(B) K = ( [HCO3¯] [OH¯] ) / [CO32¯](C) K = ( [CO32¯ ] [OH¯] ) / [HCO3¯](D) K = [CO32¯ ] / ( [CO2] [OH¯]2 )(E) K = ( [CO32¯ ] [H3O+] ) / [HCO3¯]

1989

14Aque

. Equil

.

A 55. H2PO4¯ + HBO32¯ <===> HPO42¯ + H2BO3¯The equilibrium constant for the reaction represented by the equation above is greater than 1.0. Which of the following gives the correct relative strengths of the acids and bases in the reaction?

1989

14 Acid Base

C 56. A 0.20-molar solution of a weak monoprotic acid, HA, has a pH of 3.00. The ionization constant of this acid is (A) 5.0 x 10¯7

(B) 2.0 x 10¯7

(C) 5.0 x 10¯6

(D) 5.0 x 10¯3

(E) 2.0 x 10¯3

1989

14 Acid Base


Acids Bases (A) H2PO4¯ >

H2BO3¯ and HBO32¯ > HPO42¯

(B) H2BO3¯ > H2PO4¯ and HBO32¯ >

HPO42¯ (C) H2PO4¯ >

H2BO3¯ and HPO42¯ > HBO32¯

(D) H2BO3¯ > H2PO4¯ and HPO42¯ >

HBO32¯ (E) H2PO4¯ =

H2BO3¯ and HPO42¯ = HBO32¯

AP MULTIPLE CHOICE PROBLEMSE 22. HSO4¯ + H2O <===> H3O+ + SO42¯ In the equilibrium

represented above, the species that act as bases include which of the following? I. HSO4¯II. H2OIII. SO42¯(A) II only(B) III only(C) I and II(D) I and III(E) II and III

1994

14 Acid Base

C 31. R. H2C2O4 + 2 H2O <===> 2 H3O+ + C2O42¯ Oxalic acid, H2C2O4, is a diprotic acid with K1 = 5 x 10¯2 and K2 = 5 x 10¯5. Which of the following is equal to the equilibrium constant for the reaction represented above?(A) 5 x 10¯2

(B) 5 x 10¯5

(C) 2.5 x 10¯6

(D) 5 x 10¯7

(E) 2.5 x 10¯8

1994

14 Acid Base

E 50. Which of the following acids can be oxidized to form a stronger acid?(A) H3PO4(B) HNO3(C) H2CO3(D) H3BO3(E) H2SO3

1994

14 Acid Base

B 61. A 1-molar solution of which of the following salts has the highest pH ?(A) NaNO3(B) Na2CO3(C) NH4Cl(D) NaHSO4(E) Na2SO4

1994

14 Acid Base

D 66. What is the pH of a 1.0 x 10¯2-molar solution of HCN? (Ka = 4.0 x 10¯10.)(A) 10(B) Between 7 and 10(C) 7(D) Between 4 and 7(E) 4

1994

14 Acid Base

B 38. A molecule or an ion is classified as a Lewis acid if it (A) accepts a proton from water(B) accepts a pair of electrons to form a bond(C) donates a pair of electrons to form a bond(D) donates a proton to water(E) has resonance Lewis electron-dot structures

1999

14 Acid Base


AP MULTIPLE CHOICE PROBLEMSD 45. What is the H+(aq) concentration in 0.05 M HCN (aq) ? (The Ka

for HCN is 5.0 x 10¯10) (A) 2.5 x 10¯11

(B) 2.5 x 10¯10

(C) 5.0 x 10¯10

(D) 5.0 x 10¯6

(E) 5.0 x 10¯4

1999

14 Acid Base

E 64. The net ionic equation for the reaction that occurs during the titration of nitrous aicd with sodium hydroxide is (A) HNO2 + Na+ + OH¯ ---> NaNO2 + H2O(B) HNO2 + NaOH ---> Na+ + NO2¯ + H2O(C) H+ + OH¯ --->H2O(D) HNO2 + H2O ---> NO2¯ + H3O+

(E) HNO2 + OH¯ ---> NO2¯ + H2O

1984

15Rxns

06 TEST

D 74. How many moles of NaF must be dissolved in 1.00 liter of a saturated solution of PbF2 at 25 °C to reduce the [Pb2+] to 1 x 10¯6 molar? (Ksp of PbF2 at 25 °C = 4.0 x 10¯8)(A) 0.020 mole(B) 0.040 mole(C) 0.10 mole(D) 0.20 mole(E) 0.40 mole

1984

15 Ksp

D 81. What is the net ionic equation for the reaction that occurs when aqueous copper(II) sulfate is added to excess 6-molar ammonia?(A) Cu2+ + SO42¯ + 2 NH4+ + 2 OH¯ ---> (NH4)2SO4 + Cu(OH)2(B) Cu2+ + 4 NH3 + 4 H2O --> Cu(OH)42¯ + 4 NH4+

(C) Cu2+ + 2 NH3 + 2 H2O --> Cu(OH)2 + 2 NH4+

(D) Cu2+ + 4 NH3 --> Cu(NH3)42+

(E) Cu2+ + 2 NH3 + H2O --> CuO + 2 NH4+

1984

15 Rxns

D 63. On the basis of the information below, a buffer with a pH = 9 can best be made by using(A) pure NaH2PO4(B) H3PO4 + H2PO4¯(C) H2PO4¯ + PO43¯(D) H2PO4¯ + HPO42¯(E) HPO42¯ + PO43¯

1984

15 Acid Base


Acid Acid DissociationConstant, Ka

H3PO4 7 x 10¯3 H2PO4¯ 8 x 10¯8 HPO42¯ 5 x 10¯13

AP MULTIPLE CHOICE PROBLEMSC 19. In the titration of a weak acid of unknown concentration with a

standard solution of a strong base, a pH meter was used to follow the progress of the titration. Which of the following is true for this experiment?(A) The pH is 7 at the equivalence point.(B) The pH at the equivalence point depends on the indicator used.(C) The graph of pH versus volume of base added rises gradually at first and then much more rapidly.(D) The graph of pH versus volume of base added shows no sharp rise.(E) The [H+] at the equivalence point equals the ionization constant of the acid.

1989

15 Lab

D 35. When phenolphthalein is used as the indicator in a titration of an HCl solution with a solution of NaOH, the indicator undergoes a color change from clear to red at the end point of the titration. This color change occurs abruptly because(A) phenolphthalein is a very strong acid that is capable of rapid dissociation(B) the solution being titrated undergoes a large pH change near the end point of the titration(C) phenolphthalein undergoes an irreversible reaction in basic solution(D) OH¯ acts as a catalyst for the decomposition of phenolphthalein(E) phenolphehalein is involved in the rate-determining step of the reaction between H3O+ and OH¯

1989

15 Lab

E 52. The test for the presence of Ag+ in an unknown solution involves the treatment of the solver-ammonia complex with dilute hydrochloric acid. The appearance of a white precipitate at this point indicates the presence of silver ion in the original sample. The net ionic equation that represents this test is (A) Ag(NH4)4+ + 4 H+ <===> Ag(s) + 4 NH4+

(B) Ag(NH4)4+ + Cl¯ <===> AgCl(s) + 4 NH4+

(C) Ag(NH3)4+ + 4 HCl <===> AgCl(s) + 4 NH4+ + 3 Cl#175;(D) Ag(NH3)4+ + Cl¯ <===> Ag(NH3)2Cl(s)(E) Ag(NH3)4+ + 2 H+ + Cl#175; <===> AgCl(s) + 2 NH4+

1989

15Aque

. Equil

.

C 65. The solubility of CuI is 2 x 10¯6 molar. What is the solubility product constant, Ksp, for CuI?(A) 1.4 x 10¯3

(B) 2 x 10¯6

(C) 4 x 10¯12

(D) 2 x 10¯12

(E) 8 x 10¯18

1989

15 Ksp


AP MULTIPLE CHOICE PROBLEMSD 66. MnS(s) + 2 H+ <===> Mn2+ + H2S(g) At 25 °C the solubility

product constant, Ksp, for MnS in 5 x 10¯15 and the acid dissociation constants K1 and K2 for H2S are 1 x 10¯7 and 1 x 10¯13, respectively. What is the equilibrium constant for the reaction represented by the equation above at 25 °C?(A) 1 x 10¯13 / 5 x 10¯15

(B) 5 x 10¯15 / 1 x 10¯7

(C) 1 x 10¯7 / 5 x 10¯20

(D) 5 x 10¯15 / 1 x 10¯20

(E) 1 x 10¯20 / 5 x 10¯15

1989

15 Ksp

A 69. A white solid is observed to be insoluble in water, insoluble in excess ammonia solution, and soluble in dilute HCl. Which of the following compounds could the solid be?(A) CaCO3(B) BaSO4(C) Pb(NO3)2(D) AgCl(E) Zn(OH)2

1989

15Aque

. Equil

.

B 74. Equal volumes of 0.10-molar H3PO4 and 0.20-molar KOH are mixed. After equilibrium is established, the type of ion an solution in largest concentration, other than the K+ ion, is(A) H2PO4¯(B) HPO42¯(C) PO43¯(D) OH¯(E) H3O+

1989

15 Rxns

ADB

8. Use these answers for questions 8 - 10.(A) a solution with a pH less than 7 that is not a buffer solution(B) a buffer solution with a pH between 4 and 7(C) a buffer solution with a pH between 7 and 10(D) a solution with a pH greater than 7 that is not a buffer solution(E) a solution with a pH of 7 Ionization ConstantsCH3COOH = 1.8 x 10¯5

NH3 = 1.8 x 10¯5

H2CO3; K1 = 4 x 10¯7

H2CO3; K2 = 4 x 10¯11 8. A solution prepared to be initially 1 M in NaCl and 1 M in HCl.9. A solution prepared to be initially 1 M in Na2CO3 and 1 M in CH3COONa10. A solution prepared to be initially 0.5 M in CH3COOH and 1 M in CH3COONa

1989

15 Acid Base


AP MULTIPLE CHOICE PROBLEMSB 16. R. Commercial vinegar was titrated with NaOH solution to

determine the content of acetic acid, HC2H3O2. For 20.0 milliliters of the vinegar, 32.0 milliliters of 0.500-molar NaOH solution was required. What was the concentration of acetic acid in the vinegar if no other acid was present?(A) 1.60 M(B) 0.800 M(C) 0.640 M(D) 0.600 M(E) 0.400 M

1994

15Rxns

06 TEST

A 65. Barium sulfate is LEAST soluble in a 0.01-molar solution of which of the following?(A) Al2(SO4)3(B) (NH4)2SO4(C) Na2SO4(D) NH3(E) BaCl2

1994

15

Aque.

SolnsPreci

p

A 74. A solution of calcium hypochlorite, a common additive to swimming-pool water, is(A) basic because of the hydrolysis of the OCl¯ ion(B) basic because Ca(OH)2 is a weak and insoluble base(C) neutral if the concentration is kept below 0.1 molar(D) acidic because of the hydrolysis of the Ca2+ ions(E) acidic because the acid HOCl is formed

1994

15 Acid Base

B62. HC2H3O2(aq) + CN¯(aq) <===> HCN(aq) + C2H3O2¯(aq) The reaction represented above has an equilibrium constant equal to 3.7 x 104. Which of the following can be concluded from this information? A) CN¯(aq) is a stronger base than C2H3O2¯(aq)B) HCN(aq) is a stronger acid than HC2H3O2(aq)C) The conjugate base of CN¯(aq) is C2H3O2¯(aq)D) The equilibrium constant will increase with an increase in temperature.E) The pH of a solution containing equimolar amounts of CN¯(aq) and HC2H3O2(aq) is 7.0.

1999

15 Acid Base

D 65. Which of the following compounds is NOT appreciably soluble in water but is soluble in dilute hydrochloric acid? A) Mg(OH)2(s)B) (NH4)2CO3(s)C) CuSO4(s)D) (NH4)2SO4(s)E) Sr(NO3)2(s)

1999

15SolnsPreci

p


AP MULTIPLE CHOICE PROBLEMSA 67. What is the molar solubility in water of Ag2CrO4? (The Ksp for

Ag2CrO4 is 8 x 10¯12.)A) 8 x 10¯12 MB) 2 x 10¯12 MC) (4 x 10¯12 M)1/2

D) (4 x 10¯12 M)1/3

E) (2 x 10¯12 M)1/3

1999

15 Ksp

CEA

9. -12 refer to aqueous solutions containing 1:1 mole ratios of the following pairs of substances. Assume all concentrations are 1 M. (A) NH3 and NH4Cl(B) H3PO4 and NaH2PO4(C) HCl and NaCl(D) NaOH and NH3(E) NH3 and HC2H3O2 (acetic acid) 9. The solution with the lowest pH10. The most nearly neutral solution11. A buffer at a pH > 8

1999

15 Acid Base

C 56. A cube of ice is added to some hot water in a rigid, insulated container, which is then sealed. There is no heat exchange with the surroundings. What has happened to the total energy and the total Entrop. when the system reaches equilibrium?

1984

16

Test

Entrop

Therm

D 41. Which of the following reactions has the largest positive value of S per mole of Cl2(A) H2(g) + Cl2(g) ---> 2 HCl(g)(B) Cl2(g) + 1/2 O2(g) ---> Cl2O(g)(C) Mg(s) + Cl2(g) ---> MgCl2(s)(D) 2 NH4Cl(s) ---> N2(g) + 4 H2(g) + Cl2(g)(E) Cl2(g) ---> 2 Cl(g)

1989

16Tes

t

Entrop

Therm

C 53. Which of the following must be true for a reaction that proceeds spontaneously from initial standard state conditions?(A) G° > 0 and Keq > 1(B) G° > 0 and Keq < 1(C) G° < 0 and Keq > 1(D) G° < 0 and Keq > 1(E) G° = 0 and Keq = 1

1989

16Tes

t

EquilTher

m


Energy Entrop. (A) Remains

constant Remains constant

(B) Remains constant Decreases

(C) Remains constant Increases

(D) Decreases Increases (E) Increases Decreases

AP MULTIPLE CHOICE PROBLEMSE 70. H2O(s) ---> H2O(l) When ice melts at its normal melting point,

273.16 K and 1 atmosphere, which of the following is true for the process shown above?(A) H < 0, S > 0, V > 0(B) H < 0, S < 0, V > 0(C) H > 0, S < 0, V < 0(D) H > 0, S > 0, V > 0(E) H > 0, S > 0, V < 0

1989

1617

EquilTher

m

D 35. For which of the following processes would S have a negative value?I. 2 Fe2O3(s) ---> 4 Fe(s) + 3 O2(g)II. Mg2+ + 2 OH¯ ---> Mg(OH)2(s)III. H2(g) + C2H4(g) ---> 3 C2H6(g)(A) I only(B) I and II only(C) I and III only(D) II and III only(E) I, II, and III

1994

16Tes

t

Entrop

Therm

B 58. N2(g) + 3 H2(g) ---> 2 NH3(g) The reaction indicated above is thermodynamically spontaneous at 298 K, but becomes nonspontaneous at higher temperatures. Which of the following is true at 298 K?(A) G, H, and S are all positive.(B) G, H, and S are all negative.(C) G and H are negative, but S is positive.(D) G and S are negative, but H is positive.(E) G and H are positive, but S is negative.

1994

16

Test

Entrop

Gibbs

Therm

A 66. When solid ammonium chloride, NH4Cl(s) is added to water at 25 °C, it dissolves and the temperature of the solution decreases. Which of the following is true for the values of H and S for the dissolving process?

1999

16Tes

t

Entrop

Therm

E 22. Of the following reaction, which involves the largest decrease in Entrop.? (A) CaCO3(s) ---> CaO(s) + CO2(g)(B) 2 CO(g) + O2(g) ---> 2 CO2(C) Pb(NO3)3 + 2 KI ---> PbI2 + 2 KNO3(D) C3H8 + O2 ---> 3 CO2 + 4 H2O(E) 4 La + 3 O2 ---> 2 La2O3

1999

16Tes

t

Entrop

Therm


H S A) Postive Positive B) Positive Negative C) Positive Equal to

zero D) Negativ

e Positive

E) Negative Negative

AP MULTIPLE CHOICE PROBLEMSBDCB

14. Questions 14-17The spontaneous reaction that occurs when the cell above operates is: 2Ag+ + Cd(s) ---> 2 Ag(s) + Cd2+

(A) Voltage increases.(B) Voltage decreases but remains at zero.(C) Voltage becomes zero and remains at zero.(D) No change in voltage occures.(E) Direction of voltage change cannot be predicted without additional information. Which of the above occurs for each of the following circumstances? 14. A 50-milliliter sample of a 2-molar Cd(NO3)2 solution is added to the left beaker.15. The silver electrode is made larger.16. The salt bridge is replaced by a platinum wire17. Current is allowed to flow for 5 minutes

1984

17 Electro

A 29. Cu(s) + 2 Ag+ ---> Cu2+ + 2 Ag(s) If the equilibrium constant for the reaction above is 3.7 x 1015, which of the following correctly describes the standard voltage, E°, and the standard free energy change, G°, for this reaction?(A) E° is positive and G° is negative.(B) E° is negative and G° is positive.(C) E° and G° are both positive.(D) E° and G° are both negative.(E) E° and G° are both zero

1984

17 Electro

B 46. If 0.060 faraday is passed through an electrolytic cell containing a solution of In3+ ions, the maximum number of moles of In that could be deposited at the cathode is (A) 0.010 mole(B) 0.020 mole(C) 0.030 mole(D) 0.060 mole(E) 0.18 mole

1984

17 Electro

A 83. NH3(g) + 2 CH4(g) + 5/2 O2(g) <===> H2NCH2COOH(s) + 3 H2O(l)At constant temperature, H, the change in enthalpy for the reaction above is approximately equal to(A) E - (11/2)RT(B) E - (7/2)RT(C) E + RT(D) E + (7/2)RT(E) E (11/2)RT

1984

17 Electro


AP MULTIPLE CHOICE PROBLEMSD 75. If a copper sample

containing some zinc impurity is to be purified by electrolysis, the anode and the cathode must be which of the following?

1989

17 Electro

D 60. The standard reduction potentials for two half reactions are given above. The Nernst equation for a galvanic cell at 25° C in which Fe(s) reduces Ni2+ is the following.E = E° - 0.059/2 log [Fe2+] / [Ni2+]What is the equilibrium constant for the reaction below?Fe(s) + Ni2+ ---> Fe2+ + Ni(s)(A) 1.9 x 10¯23

(B) 7.6 x 10¯8

(C) 3.6 x 10+3

(D) 1.3 x 10+7

(E) 5.2 x 10+22

1989

17 Electro

C 36. Zn(s) + Cu2+ ---> Zn2+ + Cu(s)An electrolytic cell based on the reaction represented above was constructed from zinc and copper half-cells. The observed voltage was found to be 1.00 volt instead of the standard cell potential, E°, of 1.10 volts. Which of the following could correctly account for this observation?(A) The copper electrode was larger than the zinc electrode.(B) The Zn2+ electrolyte was Zn(NO3)2, while the Cu2+ electrolyte was CuSO4.(C) The Zn2+ solution was more concentrated than the Cu2+ solution.(D) The solutions in the half-cells had different volumes.(E) The salt bridge contained KCl as the electrolyte.

1994

17 Electro

B 63R. Which of the following expressions is correct for the maxirnum mass of copper, in grams, that cou1d be plated out by electrolyzing aqueous CuCl2 for 16 hours at a constant current of 3.0 amperes? (1 faraday = 96,500 coulombs)(A) [(16)(3,600)(3.0)(63.55)(2)] / (96,500)(B) [(16)(3,600)(3.0)(63.55)] / [(96,500)(2)](C) [(16)(3,600)(3.0)(63.55)] / (96,500)(D) [(16)(60)(3.0)(96,500)(2)] / (63.55)(E) [(16)(60)(3.0)(96,500)] / [(63.55)(2)]

1994

17 Electro


Anode Cathode (A) Pure copper Pure zinc (B) Pure zinc Pure copper

(C) Pure copper Impure copper sample

(D) Impure copper sample Pure copper

(E) Impure copper sample Pure zinc

Fe2+ + 2e¯ ---> Fe(s) E° = - 0.44 volt Ni2+ + 2e¯ ---> Ni(s) E° = - 0.23 volt

AP MULTIPLE CHOICE PROBLEMSB 75. A direct-current power supply of low voltage (less than 10

volts) has lost the markings that indicate which output terminal is positive and which is negative. A chemist suggests that the power supply terminals be connected to a pair of platinum electrodes that dip into 0.1-molar KI solution. Which of the following correctly identifies the polarities of the power supply terminals?(A) A gas will be evolved only at the positive electrode.(B) A gas will be evolved only at the negative electrode.(C) A brown color will appear in the solution near the negative electrode.(D) A metal will be deposited on the positive electrode.(E) None of the methods above will identify the polarities of the power supply terminals.

1994

17 Electro

A

C

34. Questions 34-35 refer to an electrolytic cell that involves the following half-reaction. AlF63¯ + 3 e¯ ---> Al + 6F¯ 34. Which of the following occurs in the reaction? (A) AlF 63¯ is reduced at the cathode.(B) Al is oxidized at the anode.(C) Aluminum is converted from the -3 oxidation state to the 0 oxidation state.(D) F¯ acts as a reducing agent.(E) F¯ is reduced at the cathode.

35. As steady current of 10 amperes in passed though an aluminum-production cell for 15 minutes. Which of the following is the correct expressions for calculating the number of grams of aluminum produced? (1 faraday = 96,500 coulombs)

1999

17 Electro

A

57. According to the information above, what is the standard reduction potential for the half-reaction M3+(aq) + 3 e¯ --> M(s)? A) -1.66 VB) -0.06 VC) 0.06 VD) 1.66 VE) 3.26 V

1999

17 Electro

C 30. When 84-Po-214 decays, the emission consists consecutively of an alpha particle, then two beta particles, and finally another alpha particle. The resulting stable nucleus is (A) 83-Bi-206(B) 83-Bi-210(C) 82-Pb-206(D) 82-Pb-208(E) 81-Tl-210

1984

18 Nuke


M(s) + 3 Ag+(aq) --> 3 Ag(s) + 3+(aq)

E = +2.46 V

Ag+(aq) + e¯ --> Ag(s) E = +0.80 V

AP MULTIPLE CHOICE PROBLEMSA 38. The radioactive decay of 6-C-14 to 7-N-14 occurs by the

process of (A) beta particle emission (B) alpha particle emission(C) positron emission(D) electron capture(E) neutron capture

1984

18 Nuke

B 18. For the types of radiation given, which of the following is the correct order of increasing ability to penetrate a piece of lead?(A) Alpha particles < gamma rays < beta particles(B) Alpha particles < beta particles < gamma rays(C) Beta particles < alpha particles < gamma rays(D) Beta particles < gamma rays < alpha particles(E) Gamma rays < alpha particles < beta particles

1989

18 Nuke

D 38. 98-Cf-251 ---> 2n + 54-Xe-131 + __What is the missing product in the nuclear reaction represented above?(A) 42-Mo-118(B) 44-Ru-118(C) 42-Mo-120(D) 44-Ru-120(E) 46-Pd-122

1989

18 Nuke

E 68. The specific rate constant k for radioactive element X is 0.023 min -1. What weight of X wsa originally present in a sample if 40. grams is left after 60. minutes?(A) 10. grams(B) 20. grams(C) 80. grams(D) 120 grams(E) 160 grams

1989

18 Nuke

D 21. Correct statements about alpha particles include which of the following?I. They have a mass number of 4 and a charge of +2.II. They are more penetrating than beta particles.III. They are helium nuclei.(A) I only(B) III only(C) I and II(D) I and III(E) II and III

1994

18 Nuke

E 72. The nuclide 245Cm is radioactive and decays by the loss of one beta ([beta]¯) particle. The product nuclide is(A) 245Pu(B) 95Am(C) 248Cm(D) 250Cm(E) 97Bk

1994

18 Nuke


AP MULTIPLE CHOICE PROBLEMSB 48. If 87.5 percent of a sample of pure 131I decays in 24 days, what

is the half-life of 131I? (A) 6 days(B) 8 days(C) 12 days(D) 14 days(E) 21 days

1999

18 Nuke

D 77. Which of the following compounds exhibits optical isomerism?

1984

22 Org.

A 43. Which of the following pairs of compounds are isomers?

(A) (B)

(C) (D)

(E)

1994

22 Org.

E 29. The organic compound represented above is an example of (A) an organic acid(B) an alcohol(C) an ether(D) an aldehyde(E) a ketone

1999

22 Org.

A 40. The geometry of the SO3 molecule is best described as (A) trigonal planar(B) trigonal pyramidal(C) square pyramidal(D) bent (E) tetrahedral

1984

8910

Bonds

E 31. A 0.1-molar solution of which of the following ions is orange?(A) Fe(H2O)42+

(B) Cu(NH3)42+

(C) Zn(OH)42¯(D) Zn(NH3)42+

(E) Cr2O72¯

1984

Lab Lab


AP MULTIPLE CHOICE PROBLEMSD 35. The addition of an oxidizing agent such as chlorine water to a

clear solution of an unknown compound results in the appearance of a brown color. When this solution is shaken with the organic solvent, methylene dichloride, the organic solvent layer turns purple. The unknown compound probably contains(A) K+

(B) Br¯(C) NO3¯(D) I¯(E) Co2+

1984

Lab Lab

D 62. A student pipetted five 25.00-milliliter samples of hydrochloric acid and transferred each sample to an Erlenmeyer flask, diluted it with distilled water, and added a few drops of phenolphthalein to each. Each sample was then titrated with a sodium hydroxide solution to the appearance of the first permanent faint pink color. The following results were obtained.Volumes of NaOH SolutionFirst Sample..................35.22 mLSecond Sample..............36.14 mLThird Sample.................36.13 mLFourth Sample..............36.15 mLFifth Sample..................36.12 mL Which of the following is the most probable explanation for the variation in the student's results?(A) The burette was not rinsed with NaOH solution.(B) The student misread a 5 for a 6 on the burette when the first sample was titrated.(C) A different amount of water was added to the first sample.(D) The pipette was not rinsed with the HCI solution.(E) The student added too little indicator to the first sample.

1984

Lab Lab

B 36. Appropriate laboratory procedures include which of the following?I. Rinsing a buret with distilled water just before filling it with the titrant for the first titrationII. Lubricating glass tubing before inserting it into a stopperIII. For accurate results, waiting until warm or hot objects have reached room temperature before weighing them (A) II only(B) I and II only(C) I and III only(D) II and III only(E) I, II, and III

1989

Lab Lab


AP MULTIPLE CHOICE PROBLEMSA 73. Adding water to some chemicals can be dangerous because

large amounts of heat are liberated. Which of the following does NOT liberate heat when water is added to it?(A) KNO3(B) NaOH(C) CaO(D) H2SO4(E) Na

1989

Lab Genl Info

C 38. Concentrations of colored substances are commonly measured by means of a spectrophotometer. Which of the following would ensure that correct values are obtained for the measured absorbance?I. There must be enough sample in the tube to cover the entire light path.II. The instrument must be periodically reset using a standard.III. The solution must be saturated.(A) I only(B) II only(C) I and II only(D) II and III only(E) I, II, and III

1994

Lab Lab

D 41. A strip of metallic scandium, Sc, is placed in a beaker containing concentrated nitric acid. A brown gas rapidly forms, the scandium disappears, and the resulting liquid is brown-yellow but becomes colorless when warmed. These observations best support which of the following statements?(A) Nitric acid is a strong acid.(B) In solution scandium nitrate is yellow and scandium chloride is color less.(C) Nitric acid reacts with metals to form hydrogen.(D) Scandium reacts with nitric acid to form a brown gas.(E) Scandium and nitric acid react in mole proportions of 1 to 3.

1994

Lab Lab

E 46. Which of the following solids dissolves in water to form a colorless solution?(A) CrCl3(B) FeCl3(C) CoCl2(D) CuCl2(E) ZnCl2

1994

LabSolnsPreci

p


AP MULTIPLE CHOICE PROBLEMSB 52. When dilute nitric acid was added to a solution of one of the

following chemicals, a gas was evolved, This gas turned a drop of limewater, Ca(OH)2, cloudy, due to the formation of a white precipitate. The chemical was(A) household ammonia, NH3(B) baking soda, NaHCO3(C) table salt, NaCl(D) epsom salts, MgSO4 . 7H2O(E) bleach, 5% NaOCl

1994

Lab Lab

E 67. Substances X and Y that were in a solution were separated in the laboratory using the technique of fractional crystallization. This fractional crystallization is possible because substances X and Y have different(A) boiling points(B) melting points(C) densities(D) crystal colors(E) solubilities

1994

Lab Lab

C 69. Correct procedures for a titration include which of the following?I. Draining a pipet by touching the tip to the side of the container used for the titrationII. Rinsing the buret with distilled water just before filling it with the liquid to be titratedIII. Swirling the solution frequently during the titration(A) I only(B) II only(C) I and III only(D) II and III only(E) I, II, and III

1994

Lab Lab

A 70. To determine the molar mass of a solid monoprotic acid, a student titrated a weighed sample of the acid with standardized aqueous NaOH. Which of the following could explain why the student obtained a molar mass that was too large?I. Failure to rinse all acid from the weighing paper into the titration vesselII. Addition of more water than was needed to dissolve the acidIII. Addition of some base beyond the equivalence point(A) I only(B) III only(C) I and II only(D) II and III only(E) I, II, and III

1994

Lab Lab


AP MULTIPLE CHOICE PROBLEMSB 21. When a solution of sodium chloride is vaporized in a flame, the

color of the flame is (A) blue(B) yellow(C) green(D) violet(E) White

1999

Lab Lab

D 24. The safest and most effective emergency procedure to treat an acid splash on skin is to do which of the following immediately? (A) Dry the affected area with paper towels(B) Sprinkle the affected area with powdered Na2SO4(s)(C) Flush the affected area with water and then with a dilute NaOH solution(D) Flush the affected area with water and then with a dilute NaHCO3 solution(E) Flush the affected area with water and then with a dilute vinegar solution

1999

Lab Lab

A 27. Appropriate uses of a visible-light spectrophtometer include which of the following? I. Determining the concentration of a solution of Cu(NO3)2II. Measuring the conductivity of a solution of KMnO4III. Determining which ions are present in a solution that may contain Na+, Mg2+, Al3+

(A) I only(B) II only(C) III only(D) I and II only(E) I and III only

1999

Lab Lab

C 46. Which of the following occurs when excess concentrated NH3(aq) is mixed thoroughly with 0.1 M Cu(NO3)2(aq) ? (A) A dark red precipitate forms and settles out.(B) Separate layers of immiscible liquids form with a blue layer on top.(C) The color of the solution turns from light blue to dark blue.(D) Bubbles of ammonia gas form.(E) The pH of the solution decreases.

1999

Lab Lab

A 72. After completing an experiment to determine gravimetrically the percentage of water in a hydrate, a student reported a value of 38 percent. The correct value for the percentage of water in the hydrate is 51 percent. Which of the following is the most likely explanation for this difference? A) Strong initial heating caused some of the hydrate sample to spatter out of the crucible.B) The dehydrated sample absorbed moisture after heating.C) The amount of the hydrate sample used was too small.D) The crucible was not heated to constant mass before use.E) Excess heating caused the dehydrated sample to decompose.

1999

Lab Lab


AP MULTIPLE CHOICE PROBLEMSE 20. .....Mg(s) + .....NO3¯(aq) +.....H+(aq) --->......Mg2+(aq)

+ ....NH4+(aq) + ....H2O(l)When the skeleton equation above is balanced and all coefficients reduced to their lowest whole-number terms. what is the coeficient for H+ ?(A) 4(B) 6(C) 8(D) 9(E) 10

1984

RXN

06 TES

TRxnsRedo

x

A 32. The net ionic equation for the reaction between silver carbonate and hydrochloric acid is(A) Ag2CO3(s) + 2 H+ + 2 Cl¯ ---> 2 AgCl(s) + H2O + CO(g)(B) 2 Ag+ + CO32¯ + 2 H+ + 2 Cl¯ ---> 2 AgCl(s) + H2O + CO2(g)(C) CO32¯ + 2 H+ ---> H2O + CO2(g)(D) Ag+ + Cl¯ ---> AgCl(s)(E) Ag2CO3(s) + 2 H+ ---> 2Ag+ + H2CO3

1984

RXN Rxns

D 34. ...CrO2¯ + ...OH¯ ---> ... CrO42¯ + ... H2O + ... e¯ When the equation for the half-reaction above is balanced, what is the ratio of the coefficients OH¯ / CrO2¯ ?(A) 1:1(B) 2:1(C) 3:1(D) 4:1(E) 5:1

1984

RXN

RxnsRedo

x

B 42. Metallic copper is heated strongly with concentrated sulfuric acid. The products of this reaction are(A) CuSO4(s) and H2(g) only(B) Cu2+, SO2(g), and H2O(C) Cu2+, H2(g), and H2O(D) CuSO4(s), H2(g), and SO2(g)(E) Cu2+, SO3(g), and H2O

1984

RXN Rxns

A 45. The alkenes are compounds of carbon and hydrogen with the Genl formula CnH2n. If 0.561 gram of any alkene is burned in excess oxygen, what number of moles of H2O is formed?(A) 0.0400 mole(B) 0.0600 mole(C) 0.0800 mole(D) 0.400 mole(E) 0.800 mole

1984

RXN Rxns

D 61. When a solution of potassium dichromate is added to an acidified solution of iron(II) sulfate, the products of the reaction are (A) FeCr2O7(s) and H2O(B) FeCrO4(s) and H2O(C) Fe3+, CrO42¯, and H2O(D) Fe3+, Cr3+, and H2O(E) Fe2(SO4)3(s), Cr3+ and H2O

1984

RXN

RxnsRedo

x


AP MULTIPLE CHOICE PROBLEMSE 65. Which of the following species CANNOT function as an oxidizing

agent?(A) Cr2O72¯(B) MnO4¯(C) NO3¯(D) S(E) I¯

1984

RXN

RxnsRedo

x

E 79. 5 Fe2+ + MnO4¯ + 8 H+ <===> 5 Fe3+ + Mn2+ + 4 H2OIn a titration experiment based on the equation above, 25.0 milliliters of an acidified Fe2+ solution requires 14.0 milliliters of standard 0.050-molar MnO4¯ solution to reach the equivalence point. The concentration of Fe2+ in the original soluiton is(A) 0.0010 M(B) 0.0056 M(C) 0.028 M(D) 0.090 M(E) 0.14 M

1984

RXN

RxnsRedo

x

E 20. 6 I¯ + 2 MnO4¯ + 4 H2O(l) ---> 3 I2(s) + 2 MnO2(s) + OH¯Which of the following statements regarding the reaction represented by the equation above is correct?(A) Iodide ion is oxidized by hydroxide ion.(B) MnO4¯ is oxidized by iodide ion. (C) The oxidation number of manganese changes from +7 to +2.(D) The oxidation number of manganese remains the same.(E) The oxidation number of iodine changes from -1 to 0.

1989

RXN

06 TES

TRxnsRedo

x

D 22. __ Cr2O72¯ + __ e¯ + __ H+ ---> __ Cr3+ + __ H2O(l) When the equation for the half reaction above is balanced with the lowest whole-number coefficients, the coefficient for H2O is(A) 2(B) 4(C) 6(D) 7(E) 14

1989

RXN

RxnsRedo

x

D 37. __ CH3CH2COOH(l) + __ O2(g) ---> __ CO2(g) + __ H2O(l)How many moles of O2 are required to oxidize 1 mole of CH3CH2COOH according to the reaction represented above?(A) 2 moles(B) 5/2 moles(C) 3 moles(D) 7/2 moles(E) 9/2 moles

1989

RXN

06 TES

TRxns


AP MULTIPLE CHOICE PROBLEMSE 44. The metal calcium reacts with molecular hydrogen to form a

compound. All of the following statements concerning this compound are true EXCEPT:(A) Its formula is CaH2.(B) It is ionic.(C) It is solid at room temperatur(E) (D) When added to water, it reacts to produce H2 gas.(E) When added to water, it forms an acidic solution.

1989

RXN Rxns

B 61. When acidified K2Cr2O7 solution is added to Na2S solution, green Cr3+ ions and free S are formed. When acidified K2Cr2O7 solution is added to NaCl, no change occurs. Of the substances involved in these reactions, which is the best reducing agent?(A) K2Cr2O7(B) Na2S(C) Cr3+

(D) S(E) NaCl

1989

RXN

RxnsRedo

x

B 67. BrO3¯ + 5 Br¯ + 6 H+ <===> 3 Br2 + 3 H2OIf 25.0 milliliters of 0.200-molar BrO3¯ is mixed with 30.0 milliliters of 0.450-molar Br¯ solution that contains a large excess of H+, the amount of Br2 formed, according to the equation above, is(A) 5.00 x 10¯3 mole(B) 8.10 x 10¯3 mole(C) 1.35 x 10¯2 mole(D) 1.50 x 10¯2 mole(E) 1.62 x 10¯2 mole

1989

RXN Rxns

E 18. 2 H2O + 4 MnO4¯ + 3 ClO2¯ ---> 4 MnO2 + 3 ClO4¯ + 4 OH¯ Which species acts as an oxidizing agent in the reaction represented above?(A) H2O(B) ClO4¯(C) ClO2¯(D) MnO2(E) MnO4¯

1994

RXN

04/05

TEST

RxnsRedo

x

D 20. . . . Ag+ + . . . AsH3(g) + . . . OH¯ ---> . . . Ag(s) + . . . H3AsO3(aq) + . . . H2OWhen the equation above is balanced with lowest whole-number coefficients, the coefficient for OH¯ is(A) 2(B) 4(C) 5(D) 6(E) 7

1994

RXN

RxnsRedo

x


AP MULTIPLE CHOICE PROBLEMSA 29. When an aqueous solution of NaOH is added to an aqueous

solution of potassium dichromate, K2Cr2O7 the dichromate ion is converted to(A) CrO42¯(B) CrO2(C) Cr3+

(D) Cr2O3(s)(E) Cr(OH)3(s)

1994

RXN Rxns

C 55. What volume of 0.150-molar HCl is required to neutralize 25.0 milliliters of 0.120-molar Ba(OH)2?(A) 20.0 mL(B) 30 0 mL(C) 40.0 mL(D) 60.0 mL(E) 80.0 mL

1994

RXN

04/05

TEST

Rxns

B 56. It is suggested that SO2 (molar mass 64 grams), which contributes to acid rain, could be removed from a stream of waste Gas by bubbling the Gas through 0.25-molar KOH, thereby producing K2SO3. What is the maximum mass of SO2 that could be removed by 1,000. liters of the KOH solution?(A) 4.0 kg(B) 8.0 kg(C) 16 kg(D) 20. kg(E) 40. kg

1994

RXN Rxns

DD

59. R. When a 1.25-gram sample of limestone was dissolved in acid, 0.44 gram of CO2 was generated. If the rock contained no carbonate other than CaCO3, what was the percent of CaCO3 by mass in the limestone? (A) 35%(B) 44%(C) 67%(D) 80%(E) 100%

1994

RXN

06 TES

TStoic

C 71 ... Fe(OH)2 + ... O2 + ... H2O ---> ... Fe(OH)3If 1 mole of O2 oxidizes Fe(OH)2 according to the reaction represented above, how many moles of Fe(OH)3 can be formed?(A) 2(B) 3(C) 4(D) 5(E) 6

1994

RXN

RxnsRedo

x


AP MULTIPLE CHOICE PROBLEMSEA

17. Question 17-18 refer to the following elements. (A) Lithium(B) Nickel(C) Bromine(D) Uranium (E) Fluorine 17. Is a gas in its standard state at 298 K 18. Reacts with water to form a strong base

1999

RXN

Genl Info

B 20. What mass of Au is produced when 0.0500 mol of Au2S3 is reduced completely with excess H2? (A) 9.85 g(B) 19.7 g(C) 24.5 g(D) 39.4 g(E) 48.9 g

1999

RXN

06 TES

TRxns

C 26. . . .C10H12O4S(s) + . . O2(g) ---> . . . CO2(g) + . . . SO2(g) + . . . H2O(g) When the equation above is balanced and all coefficients are reduced to their lowest whole-number terms, the coefficient for O2(g) is? (A) 6(B) 7(C) 12(D) 14(E) 28

1999

RXN

04/05

TEST

Stoich

C42. . . . Li3N(s) + . . . H2O(l) ---> . . . Li+ (aq) + . . . OH¯(aq) + . . . NH3(g) When the equation above is balanced and all coefficients reduced to lowest whole number terms, the coefficient for OH¯(aq) is (A) 1(B) 2(C) 3(D) 4(E) 6

1999

RXN

RxnsRedo

x

D55. 10 HI + 2 KMnO4 + 3 H2SO4 --> 5 I2 + 2 MnSO4 + K2SO4 + 8 H2O According to the balanced equation above, how many moles of HI would be necessary to produce 2.5 mol of I2, starting with 4.0 mol of KMnO4 and 3.0 mol of H2SO4? A) 20B) 10C) 8.0D) 5.0E) 2.5

1999

RXN

Stoich


Use the following answers for questions 1 - 3 · Web viewThe volume of distilled water that...

Documents

Transcript of Use the following answers for questions 1 - 3 · Web viewThe volume of distilled water that...