CHEMISTRY FINAL EXAM REVIEW GUIDE 2012 Scott

DISCLAIMER: THIS IS A SAMPLE OF QUESTIONS/PROBLEMS FROM THIS YEAR. PLEASE BE SURE TO REVIEW YOUR NOTES, LABS, COJ’S, OBJECTIVE SHEETS, ETC. DO NOT RELY ONLY ON THIS REVIEW GUIDE.

Multiple ChoiceIdentify the choice that best completes the statement or answers the question.

____ 1) Which of the following observations is quantitative?a. The liquid turns blue litmus paper red.b. The liquid boils at 100C.c. The liquid tastes bitter.d. The liquid is cloudy.

____ 2) The symbols for units of length in order from largest to smallest area. m, cm, mm, km. c. km, mm, cm, m.b. mm, m, cm, km. d. km, m, cm, mm.

____ 3) A volume of 1 milliliter is equivalent toa. 1 cubic centimeter. c. 1 liter.b. 1 gram. d. 10–1 cubic decimeters.

____ 4) Which pair of quantities determines the density of a material?a. mass and weight c. volume and concentrationb. volume and weight d. volume and mass

____ 5) A sample of gold has a mass of 96.5 g and a volume of 5.00 cm3. The density of gold isa. 0.0518 g/cm3. c. 101.5 g/cm3.b. 19.3 g/cm3. d. 483 g/cm3.

____ 6) The number of grams equal to 0.5 kg isa. 0.0005. c. 500.b. 0.005. d. 5000.

____ 7) If 1 inch equals 2.54 cm, how many centimeters equal 1 yard?a. 0.0706 cm c. 30.5 cmb. 14.2 cm d. 91.4 cm

____ 8) A chemist obtained the values 5.2246 g, 5.2353 g, and 5.2501 g for the mass of a sample. Without knowing the true mass of the sample, it can be said that these values havea. good precision.b. good accuracy.c. poor precision.d. poor accuracy.

____ 9) The measurement 0.035550 g rounded off to two significant figures would bea. 0.03 g. c. 0.036 g.b. 0.35 g. d. 3.5 102 g.

____ 10) When 64.4 is divided by 2.00, the correct number of significant figures in the result is

a. 1. c. 4.b. 3. d. 6.

____ 11) According to the law of conservation of mass, when sodium, hydrogen, and oxygen react to form a compound, the mass of the compound is ____ the sum of the masses of the individual elements.a. equal to c. less thanb. greater than d. either greater than or less than

____ 12) Which concept in Dalton's atomic theory has been modified?a. All matter is composed of atoms.b. Atoms of different elements have different properties and masses.c. Atoms can combine in chemical reactions.d. Atoms cannot be divided.

____ 13) Rutherford's experiments led him to conclude that atoms contain massive central regions that havea. a positive charge. c. no charge.b. a negative charge. d. both protons and electrons.

____ 14) Experiments with cathode rays led to the discovery of thea. proton. c. neutron.b. nucleus. d. electron.

____ 15) Whose series of experiments identified the nucleus of the atom?a. Rutherford c. Chadwickb. Dalton d. Bohr

____ 16) Because most particles fired at gold foil passed straight through, Rutherford concluded thata. atoms were mostly empty space. c. electrons formed the nucleus.b. atoms contained no charged particles. d. atoms were indivisible.

____ 17) An atom is electrically neutral becausea. neutrons balance the protons and electrons.b. nuclear forces stabilize the charges.c. the numbers of protons and electrons are equal.d. the numbers of protons and neutrons are equal.

____ 18) The atomic number of oxygen, 8, indicates that there are eighta. protons in the nucleus of an oxygen atom.b. oxygen nuclides.c. neutrons outside the oxygen atom's nucleus.d. energy levels in the oxygen atom's nucleus.

____ 19) Chlorine has atomic number 17 and mass number 35. It hasa. 17 protons, 17 electrons, and 18 neutrons.b. 35 protons, 35 electrons, and 17 neutrons.c. 17 protons, 17 electrons, and 52 neutrons.d. 18 protons, 18 electrons, and 17 neutrons.

____ 20) Phosphorus-33 containsa. 33 protons. c. 33 neutrons.b. 18 neutrons. d. 18 protons.

____ 21) The atomic number of neon is 10. The atomic number of calcium is 20. Compared with a mole of neon, a mole of calcium containsa. twice as many atoms. c. an equal number of atoms.b. half as many atoms. d. 20 times as many atoms.

____ 22) The mass of a sample containing 3.5 mol of silicon atoms is approximatelya. 28 g. c. 72 g.b. 35 g. d. 98 g.

____ 23) Refer to the figure below. To which group do fluorine and chlorine belong?

a. alkaline-earth metals c. halogensb. transition elements d. actinides

____ 24) Across a period in the periodic table, atomic radiia. gradually decrease.b. gradually decrease, then sharply increase.c. gradually increase.d. gradually increase, then sharply decrease.

____ 25) Which is the best reason that the atomic radius generally increases with atomic number in each group of elements?a. The nuclear charge increases.b. The number of neutrons increases.c. The number of occupied energy levels increases.

d. A new octet forms.

____ 26) The number of valence electrons in Group 17 elements isa. 7. c. 17.b. 8. d. equal to the period number.

____ 27) Across a period, ionization energies of d-block elements generallya. increase. c. remain constant.b. decrease. d. drop to zero.

____ 28) Among the d-block elements, as atomic radii decrease, electronegativity valuesa. remain constant. c. decrease.b. increase. d. drop to zero.

____ 29) The electrons involved in the formation of a chemical bond are calleda. dipoles. c. Lewis electrons.b. s electrons. d. valence electrons.

____ 30) If two covalently bonded atoms are identical, the bond isa. nonpolar covalent. c. dipole covalent.b. polar covalent. d. coordinate covalent.

____ 31) The B—F bond in BF3 isa. polar covalent. c. nonpolar covalent.b. ionic. d. metallic.

____ 32) In a molecule of fluorine, the two shared electrons give each fluorine atom how many electron(s) in the outer energy level?a. 1 c. 8b. 2 d. 32

____ 33) The substance whose Lewis structure shows three covalent bonds isa. H2O. c. NH3.b. CH2Cl2. d. CCl4.

____ 34) What is the correct Lewis structure for hydrogen chloride, HCl?

a. A c. Cb. B d. D

____ 35) The Lewis structure for the ammonium ion, NH4, hasa. nonpolar covalent bond. c. polar covalent bond.b. ionic bond. d. metallic bond.

____ 36) According to VSEPR theory, an AB2 molecule isa. trigonal-planar. c. linear.b. tetrahedral. d. octahedral.

____ 37) According to VSEPR theory, the structure of the ammonia molecule, NH3, is

a. trigonal-planar. c. trigonal-pyramidal.b. bent. d. tetrahedral.

____ 38) Use VSEPR theory to predict the shape of the hydrogen chloride molecule, HCl.a. tetrahedral c. bentb. linear d. trigonal-planar

____ 39) Use VSEPR theory to predict the shape of the carbon tetraiodide molecule, CI4.a. tetrahedral c. bentb. linear d. trigonal-planar

____ 40) The reason the boiling point of water (H2O) is higher than the boiling point of hydrogen sulfide (H2S) is partially explained bya. London forces. c. ionic bonding.b. covalent bonding. d. hydrogen bonding.

____ 41) The following molecules contain polar bonds. The only polar molecule isa. CCl4. c. NH3.b. CO2. d. CH4.

____ 42) When Group 2A elements form ions, they ____.a. lose two protons c. lose two electronsb. gain two protons d. gain two electrons

____ 43) What is the correct name for the N ion?a. nitrate ion c. nitride ionb. nitrogen ion d. nitrite ion

____ 44) Aluminum is a group 3A metal. Which ion does A1 typically form?a. Al c. Alb. Al d. Al

____ 45) The nonmetals in Groups 6A and 7A ____.a. lose electrons when they form ionsb. have a numerical charge that is found by subtracting 8 from the group numberc. all have ions with a –1 charged. end in -ate

____ 46) Which of the following compounds contains the Mn ion?a. MnS c. Mn Ob. MnBr d. MnO

____ 47) How are chemical formulas of ionic compounds generally written?a. cation then anionb. anion then cationc. Roman numeral first, then anion, then cationd. subscripts first, then ions

____ 48) Which of the following formulas represents an ionic compound?

a. CS c. N Ob. BaI d. PCl

____ 49) Which element, when combined with fluorine, would most likely form an ionic compound?a. lithium c. phosphorusb. carbon d. chlorine

____ 50) Which of the following shows correctly an ion pair and the ionic compound the two ions form?a. Sn , N ; Sn N c. Cr , I ; CrIb. Cu , O ; Cu O d. Fe , O ; Fe O

____ 51) Which of the following compounds contains the lead(II) ion?a. PbO c. Pb2Ob. PbCl4 d. Pb2S

____ 52) Which of the following shows both the correct formula and correct name of an acid?a. HClO , chloric acid c. H PO , phosphoric acidb. HNO , hydronitrous acid d. HI, iodic acid

____ 53) What is the formula for phosphoric acid?a. H PO c. HPOb. H PO d. HPO

____ 54) Select the correct formula for sulfur hexafluoride.a. S F c. F Sb. F SO d. SF

____ 55) What is the correct name for the compound CoCl ?a. cobalt(I) chlorate c. cobalt(II) chlorateb. cobalt(I) chloride d. cobalt(II) chloride

____ 56) What is the correct formula for barium chlorate?a. Ba(ClO) c. Ba(ClO )b. Ba(ClO ) d. BaCl

____ 57) Which of the following is the correct name for N O ?a. nitrous oxide c. nitrogen dioxideb. dinitrogen pentoxide d. nitrate oxide

____ 58) To balance a chemical equation, it may be necessary to adjust thea. coefficients. c. formulas of the products.b. subscripts. d. number of products.

____ 59) A chemical equation is balanced when thea. coefficients of the reactants equal the coefficients of the products.b. same number of each kind of atom appears in the reactants and in the products.

c. products and reactants are the same chemicals.d. subscripts of the reactants equal the subscripts of the products.

____ 60) Which equation is not balanced?a. c.b. d.

____ 61) Which coefficients correctly balance the formula ?a. 1,2,2 c. 2,1,1b. 1,1,2 d. 2,2,2

____ 62) The units of molar mass area. g/mol. c. amu/mol.b. mol/g. d. amu/g.

____ 63) In the reaction represented by the equation 2Al2O3 4Al + 3O2, what is the mole ratio of aluminum to oxygen?a. 10:6 c. 2:3b. 3:4 d. 4:3

____ 64) The Haber process for producing ammonia commercially is represented by the equation N2(g) + 3H2(g) 2NH3(g). To completely convert 9.0 mol hydrogen gas to ammonia gas, how many moles of nitrogen gas are required?a. 1.0 mol c. 3.0 molb. 2.0 mol d. 6.0 mol

____ 65) For the reaction represented by the equation 2Fe + O2 2FeO, how many grams of iron(II) oxide are produced from 8.00 mol of iron in an excess of oxygen?a. 71.8 g c. 712 gb. 575 g d. 1310 g

____ 66) For the reaction represented by the equation 2Na + Cl2 2NaCl, how many grams of sodium chloride can be produced from 500. g each of sodium and chlorine?a. 112 g c. 409 gb. 319 g d. 824 g

____ 67) For the reaction represented by the equation CH4 + 2O2 2H2O + CO2, calculate the percentage yield of carbon dioxide if 1000. g of methane react with excess oxygen to produce 2300. g of carbon dioxide.a. 83.88% c. 92.76%b. 89.14% d. 96.78%

____ 68) A catalyst is ____.a. the product of a combustion reactionb. not used up in a reactionc. one of the reactants in single-replacement reactionsd. a solid product of a reaction

____ 69) Chemical equations must be balanced to satisfy ____.a. the law of definite proportions c. the law of conservation of massb. the law of multiple proportions d. Avogadro’s principle

____ 70) In every balanced chemical equation, each side of the equation has the same number of ____.a. atoms of each element c. molesb. molecules d. coefficients

____ 71) When potassium hydroxide and barium chloride react, potassium chloride and barium hydroxide are formed. The balanced equation for this reaction is ____.a. KH BaCl KCl BaH c. 2KOH BaCl 2KCl Ba(OH)b. KOH BaCl KCl BaOH d. KOH BaCl KCl BaOH

____ 72) In order to predict whether or not a single-replacement reaction takes place, you need to consult a chart that shows the ____.a. periodic tableb. activity series of metalsc. common polyatomic ionsd. ionic charges of representative elements

____ 73) In a double-replacement reaction, the ____.a. products are always molecularb. reactants are two ionic compoundsc. reactants are two elementsd. products are a new element and a new compound

____ 74) Which of the following is a balanced equation representing the decomposition of lead(IV) oxide?a. PbO Pb 2O c. Pb O 2Pb Ob. PbO Pb O d. PbO Pb O

____ 75) The equation 2C H OH 9O 6CO 8H O is an example of which type of reaction?a. combustion reaction c. double-replacement reactionb. single-replacement reaction d. decomposition reaction

____ 76) A double-replacement reaction takes place when aqueous cobalt(III) chloride reacts with aqueous lithium hydroxide. One of the products of this reaction is ____.a. Co(OH) c. LiCob. Co(OH) d. LiCl

____ 77) If a synthesis reaction takes place between rubidium and bromine, the chemical formula for the product is ____.a. RuBr c. RbBrb. Rb Br d. RbBr

____ 78) What is the balanced chemical equation for the reaction that takes place between bromine and sodium iodide?a. Br NaI NaBr I c. Br NaI NaBrIb. Br 2NaI 2NaBr I d. Br NaI NaBr I

____ 79) Pressure is the force per unita. volume. c. length.b. surface area. d. depth.

____ 80) If force is held constant as surface area decreases, pressurea. remains constant.b. decreases.c. increases.d. increases or decreases, depending on the volume change.

____ 81) Why does a can collapse when a vacuum pump removes air from the can?a. The inside and outside forces balance out and crush the can.b. The unbalanced outside force from atmospheric pressure crushes the can.c. The atmosphere exerts pressure on the inside of the can and crushes it.d. The vacuum pump creates a force that crushes the can.

____ 82) Convert the pressure 0.840 atm to mm Hg.a. 365 mm Hg c. 638 mm Hgb. 437 mm Hg d. 780 mm Hg

____ 83) To correct for the partial pressure of water vapor in a gas collection bottle, the vapor pressure of H2O at the collecting temperature is generallya. subtracted from the partial pressure of the collected gas.b. added to the pressure of the collected gas.c. subtracted from the atmospheric pressure.d. added to the atmospheric pressure.

____ 84) A sample of oxygen occupies 560. mL when the pressure is 800.00 mm Hg. At constant temperature, what volume does the gas occupy when the pressure decreases to 700.0 mm Hg?a. 80.0 mL c. 600. mLb. 490. mL d. 640. mL

____ 85) Chlorine is produced by the reaction 2HCl(g) H2(g) + Cl2(g). How many grams of HCl (36.5 g/mol) must be used to produce 10.0 L of chlorine at STP?a. 15.8 g c. 32.6 gb. 30.2 g d. 36.5 g

____ 86) Calculate the approximate volume of a 0.600 mol sample of gas at 15.0°C and a pressure of 1.10 atm.a. 12.9 L c. 24.6 Lb. 22.4 L d. 139 L

____ 87) Why is a gas easier to compress than a liquid or a solid?a. Its volume increases more under pressure than an equal volume of liquid does.b. Its volume increases more under pressure than an equal volume of solid does.c. The space between gas particles is much less than the space between liquid or solid

particles.d. The volume of a gas’s particles is small compared to the overall volume of the gas.

____ 88) Why does the pressure inside a container of gas increase if more gas is added to the container?a. There is an increase in the number of collisions between particles and the walls of the

container.b. There is an increase in the temperature of the gas.c. There is a decrease in the volume of the gas.d. There is an increase in the force of the collisions between the particles and the walls of the

container.

____ 89) If a balloon is heated, what happens to the pressure of the air inside the balloon if the volume remains constant?a. It increases. c. It decreases.b. It stays the same. d. The change cannot be predicted.

____ 90) If a sealed syringe is heated, in which direction will the syringe plunger move?a. out c. The plunger will not move.b. in d. The direction cannot be predicted.

____ 91) If the atmospheric pressure on Mt. Everest is one-third the atmospheric pressure at sea level, the partial pressure of oxygen on Everest is ____.a. one-sixth its pressure at sea level c. one-half its pressure at sea levelb. one-third its pressure at sea level d. equal to its pressure at sea level

____ 92) Which of the following best describes temperature?a. energy as heat absorbed or released in a chemical or physical changeb. a measure of the average kinetic energy of the particles in a sample of matterc. energy in the form of heatd. energy of change

____ 93) How is a Celsius temperature reading converted to a Kelvin temperature reading?a. by adding 273.15 c. by dividing by 273.15b. by subtracting 273.15 d. by multiplying by 273.15

____ 94) What is the energy required to raise the temperature of 1 g of a substance by 1°C or 1 K?a. specific heat c. heat capacityb. heat energy d. enthalpy of formation

____ 95) How much energy does a copper sample absorb as energy in the form of heat if its specific heat is 0.384 J/(g·°C), its mass is 8.00 g, and it is heated from 10.0°C to 40.0°C?a. 0.0016 J/(g·°C) c. 92.2 Jb. 0.0016 J d. 92.2 J/(g·°C)

____ 96) Find the specific heat of a material if a 6.0 g sample absorbs 50. J when it is heated from 30°C to 50°C.a. 0.60 J c. 0.42 Jb. 0.60 J/(g·°C) d. 0.42 J/(g·°C)

____ 97) is always positive for aa. spontaneous reaction. c. exothermic reaction.b. nonspontaneous reaction. d. endothermic reaction.

____ 98) Ice melting is an example of a(n)a. exothermic reaction. c. endothermic reaction.b. negative entropic reactions. d. catalysed reaction.

____ 99) A piece of metal is heated, then submerged in cool water. Which statement below describes what happens?a. The temperature of the metal will increase.b. The temperature of the water will increase.c. The temperature of the water will decrease.d. The temperature of the water will increase and the temperature of the metal will decrease.

Short Answer

100) What is the law of conservation of mass?101) Describe the nucleus of an atom.102) What is the atomic number of an atom?103) What is the mass number of an atom?104) The element chromium has four naturally occurring isotopes. Use the relative abundance of each to calculate

the average atomic mass of chromium.

Cr = 4.34%, Cr = 83.79%, Cr = 9.50%, Cr = 2.37%.105) In terms of the periodic law, explain which two of these elements are most similar: sodium (element 11),

phosphorus (element 15), and sulfur (element 16).106) What can you predict about the properties of xenon and helium, both in Group 18 in the periodic table? Why?107) Differentiate/ compare/ contrast an ionic compound and a molecular compound.108) Why must a chemical equation be balanced to solve stoichiometry problems?109) Give at least three reasons why the actual yield of a chemical reaction could be less than the theoretical yield.110) Balance the following equation. Identify the reaction type.

Mg H PO Mg (PO ) H111) Balance the following equation. Identify the reaction type.

C H O CO H O112) Balance the following equation. Identify the reaction type.

Au O Au O113) Balance the following equation. Identify the reaction type.

Na PO ZnSO Na SO Zn (PO )114) Complete and balance the following equation. Identify the reaction type.

Al Cl 115) Complete and balance the following equation. Identify the reaction type.

Fe (SO ) Ba(OH) 116) What are standard temperature and pressure? Why is a standard necessary?117) A gas occupies a volume of 140 mL at 35.0 C and 97 kPa. What is the volume of the gas at STP?118) How many moles of N are in a flask with a volume of 250 mL at a pressure of 300.0 kPa and a temperature

of 300.0 K?119) How can a calorimeter measure energy?120) Explain the difference between heat and temperature.

121) What mass of KCl (solubility = at 20 C) can dissolve in 3.30 10 g of water?122) What is the molarity of a solution containing 9.0 moles of solute in 2500 mL of solution?123) If 1.0 mL of 6.0M HCl is added to 499 mL of water to give exactly a 500-mL solution, what is the molarity of

the dilute solution?124) If the volume of solute is 6.0 mL and the volume of solution is 300.0 mL, what is the solute's percent by

volume?125) Calculate the molality of a solution prepared by dissolving 175 g of KNO in 750 g of water.126) If you supply 36 kJ of heat, how many moles of ice at 0 C can be melted, heated to its boiling point, and

completely boiled away? ( H = 40.5 kJ/mol; H = 6.0 kJ/mol; specific heatwater = 0.0753 )

127) Use the periodic table to determine the number of electrons in a neutral atom of lithium.128) How many protons are present in an atom of Be-9?129) Write the charge of a chloride ion.130) How many atoms are present in 80.0 mol of zirconium?131) How many moles of iron are equivalent to 1.11 1025 atoms?132) Determine the mass in grams of 5.00 mol of oxygen.133) Draw a ball-and-stick model of a water molecule. Include the polarities of the bonds.What type of

intermolecular force is present in water?134) What mass of PCl3 forms in the reaction of 75.0 g P4 with 275 g Cl2 ?

135) The reaction of 100. g of salicylic acid, C7H6O3, with excess acetic anhydride produces 50.0 g of aspirin, C9H8O4, according to the equation below. What is the percentage yield for this reaction?

136) Explain nuclear charge and how it affects the general trend in radii of atoms of elements going from left to right across a period in the periodic table.

137) What determines whether one metal will replace another metal from a compound in a single-replacement reaction?

138) Predict the precipitate that forms when aqueous solutions of silver nitrate and potassium chloride react to form products in a double-replacement reaction. Include a discussion of how to write the complete chemical equation describing this reaction.

139) Explain Boyle’s pressure-volume relationship in terms of the kinetic-molecular theory.140) When a mixture of sulfur and metallic silver is heated, silver sulfide is produced. What mass of silver sulfide

is produced from a mixture of 3.0 g Ag and 3.0 g S ? 16Ag(s) + S (s) 8Ag S(s)

141) A 500-g sample of Al (SO ) is reacted with 450 g of Ca(OH) . A total of 596 g of CaSO is produced. What is the limiting reagent in this reaction, and how many moles of excess reagent are unreacted? Al (SO ) (aq) + 3Ca(OH) (aq) 2Al(OH) (s) + 3CaSO (s)

142) Discuss the different factors that can affect the solubility of a substance. Include specific examples in your discussion.

143) What is a diatomic molecule? Identify the elements that exist as diatomic molecules in nature.

144) Explain why the conversion factor cannot be used for the reaction represented by the equation

145) Determine the maximum number of moles of product that can be produced from 7.0 mol Al and 8.0 mol Cl2

according to the equation 2Al + 3Cl2 2 AlCl3.Describe in words the method used. Then show the calculation(s).

146) Explain the difference between a limiting reactant and an excess reactant.147) How can H be treated like other values in a stoichiometry problem even though it is not a physical product?148) Sulfur in gasoline can produce sulfuric acid, H2SO4, according to the two-step process shown below. For each

125 g of sulfur in gasoline, how many moles of H2SO4 will be produced?

149) What mass in grams of sodium hydroxide is produced if 20.0 g of sodium metal react with excess water according to the chemical equation 2Na(s) + 2H2O(l) 2NaOH(aq) + H2(g)?

150) In the reaction represented by the equation 2NH3 + CO2 CO(NH2)2 + H20, 30.7 g of CO(NH2)2 forms per 1.00 mol of CO2 that reacts when NH3 is in excess. What is the percentage yield?

151) Draw a Lewis structure for carbon disulfide, CS2.

CHEMISTRY FINAL EXAM REVIEW GUIDE 2012 ScottAnswer Section

MULTIPLE CHOICE

1) ANS:B

2) ANS: D3) ANS: A4) ANS: D5) ANS: B6) ANS: C7) ANS: D8) ANS: C9) ANS: C10) ANS: B11) ANS: A12) ANS: D13) ANS: A14) ANS: D15) ANS: A16) ANS: A17) ANS: C18) ANS: A19) ANS: A20) ANS: B21) ANS: C22) ANS: D23) ANS: C24) ANS: A25) ANS: C26) ANS: A27) ANS: A28) ANS: B29) ANS: D30) ANS: A31) ANS: B32) ANS: C33) ANS: C

34) ANS: D35) ANS: C36) ANS: C37) ANS: C38) ANS: B39) ANS: A40) ANS: D41) ANS: C42) ANS: C43) ANS: C44) ANS: B

45) ANS: B46) ANS: C47) ANS: A48) ANS: B49) ANS: A50) ANS: D51) ANS: A52) ANS: C53) ANS: B54) ANS: D55) ANS: D56) ANS: C57) ANS: B58) ANS: A59) ANS: B60) ANS: D61) ANS: D62) ANS: A63) ANS: D64) ANS: C65) ANS: B66) ANS: D

67) ANS: A68) ANS: B69) ANS: C70) ANS: A71) ANS: C72) ANS: B73) ANS: B74) ANS: B75) ANS: A76) ANS: A77) ANS: D78) ANS: B79) ANS: B80) ANS: C81) ANS: B82) ANS: C83) ANS: C84) ANS: D85) ANS: C86) ANS: A87) ANS: D88) ANS: A89) ANS: A90) ANS: A91) ANS: B92) ANS: B93) ANS: C94) ANS: A95) ANS: C96) ANS: D

97) ANS: D98) ANS: B99) ANS: D

SHORT ANSWER

100) The statement that mass cannot be created or destroyed in ordinary chemical reactions.101) An atom’s very small central region, which is made up of protons and neutrons.102) The number of protons in the nucleus of an atom.

103) The sum of the number of protons and neutrons in an atom.104) 50 amu 0.0434 = 2.17 amu

52 amu 0.8379 = 43.57 amu 53 amu 0.0950 = 5.04 amu 54 amu 0.0237 = 1.28 amu_________________________

= 52.06 amu 52 amu

105) Their locations in the periodic table indicate that phosphorus and sulfur are nonmetals and sodium is a metal. Nonmetals are a group with characteristic properties, so phosphorus and sulfur are the most similar elements of the three.106) In the periodic table, elements in the same column or group have similar properties. Because helium and xenon are in the same group, they have similar properties.107) Atoms in a molecular compound share electrons to achieve stability. Atoms in an ionic compound gain or lose electrons to form ions, which combine so that the number of positive and negative charges is equal.108) Only a balanced equation reveals the correct mole ratios of the reacting substances.109) The actual yield could be less than a theoretical yield for these reasons: reactants may form by-products in competing side reactions, reactants may contain impurities, and reactions may not go to completion.

110) 3Mg 2H PO Mg (PO ) 3H

111) C H 3O 3CO 3H O Combustion

112) 2Au O 4Au 3O

113) 2Na PO 3ZnSO 3Na SO Zn (PO )

114) 2Al 3Cl 2AlCl Synthesis

115) Fe (SO ) 3Ba(OH) 2Fe(OH) 3BaSO Double Replacement.116) Standard temperature is 0C, and standard pressure is 1 atm. Scientists have agreed upon standard conditions for temperature and pressure to compare volumes of gases.

117) T = 35.0 C + 273 = 308 K T = 0.0 C + 273 = 273 K

V = P V

V = 97 kPa 140 mL = 120 mL

118) 250 mL = 0.25 L

n = P = = 0.030 mol119) When energy is released or absorbed inside the chamber of a calorimeter, the temperature of the water surrounding the chamber changes. The change in energy as heat can be calculated by multiplying the mass of the water by the temperature change and by the specific heat of water.120) Energy as heat is energy that is transferred between objects. Temperature is a measure of the average kinetic energy of all the particles of a substance.

121)

122)

123)

124) % = 2.0%

125) molar mass KNO : K: 1 39.1 g = 39.1 g N: 1 14.0 g = 14.0 g O: 3 16.0 g = 48.0 g molar mass = 101.1 g

126) Total heat = heat to melt ice + heat to warm water to 100 C + heat to evaporate water

Total heat = (moles ice H ) + (moles water C T) + (moles water H )

36 kJ = (moles of H O 6.0 kJ/mol) + (moles of H O 0.0753 100 C) + (moles of H O 40.5 kJ/mol)

36 kJ = moles H O (6.0 kJ/mol + 0.0753 100 C + 40.5 kJ/mol) 36 kJ = moles H O (54.0 kJ/mol)

moles H O =

moles H O = 0.67 mol

127) 3128) 4129) –1130) 4.82 1025 atoms Zr

Solution: 131) 18.4 mol Fe

Solution: 132) 80.0 g O

Solution: 133)

-

+134) Assuming that P4 is the limiting reagent:

Assuming that Cl2 is the limiting reagent:

Since the smaller amount of product is formed from P4, it is the limiting reagent. The mass of product formed is:

135)

136) Nuclear charge is the attraction an atomic nucleus has on the electrons surrounding it. As you move from left to right across a period, the atomic number increases, and therefore the number of protons in the nucleus increases. The more protons within a nucleus, the greater is the nuclear charge. A greater nuclear charge pulls the electrons closer to the nucleus, decreasing the atomic radius.

137) Whether one metal will replace another is determined by the relative reactivity of the two metals. The activity series of metals lists metals in order of decreasing reactivity. A reactive metal will replace any metal found below it in the activity series.138) Because the reaction is a double-replacement type, cations are exchanged among compounds during the reaction. The first step is to write the equation in skeleton form:

AgNO + KCl AgCl + KNO

Inspection of this equation shows that the insoluble precipitate silver chloride forms in an aqueous solution of potassium nitrate. The relative amounts of elements are the same on either side of the equation, so the complete equation is:

AgNO (aq) + KCl(aq) AgCl(s) + KNO (aq) (balanced)

139) The pressure of a gas is caused by collisions of the gas particles with the container walls. If the volume of a container is decreased, but the same quantity of gas is present at the same temperature, there will be more molecules per unit volume. This means that there will be more gas particle-wall collisions for a given unit of wall surface. In other words, there will be greater pressure (force/area on a surface).

Conversely, if the volume of a container is increased, but the same quantity of gas is present at the same temperature, there will be fewer molecules per unit volume. This means that there will be fewer gas particle-wall collisions for a given unit of wall surface. In other words, there will be decreased pressure (force/area on a surface).140) The limiting reagent is silver.3.0 g Ag 1 mol Ag/108 g Ag = 0.03 mol Ag 3.0 g S 1 mol S /256 g S = 0.01 mol S 0.03 mol Ag 8 mol Ag S/16 mol Ag 248 g Ag S/1 mol Ag S = 3.72 g Ag S3.72 g of silver sulfide is produced.

141) 500 g Al (SO ) 1 mol Al (SO ) /342 g Al (SO ) 3 mol Ca(OH) /1 mol Al (SO ) 74 g Ca(OH)/1 mol Ca(OH) = 325 g Ca(OH)

450 g – 325 g = 125 g There are 125 g excess Ca(OH) . Al (SO ) is the limiting reagent. 125 g Ca(OH) 1 mol Ca(OH) /74 g Ca(OH) = 1.69 mol Ca(OH) There are 1.69 mol Ca(OH)2 remaining of unreacted excess reagent.

142) The factors are temperature, pressure, and the nature of the solute and solvent. Specific examples include the following. Potassium nitrate is more soluble in water at high temperature than at low temperature. Gases are less soluble at high temperatures than at low temperatures. The solubility of a particular gas increases as the partial pressure of that gas above the solution increases. Sodium nitrate is much more soluble in water than is barium sulfate, regardless of temperature, because the attractive forces between the ions in BaSO are stronger than the attractive force of the solvent molecules.143) HONClBrIF144) This conversion factor uses coefficients to compare mass directly. Ratios of moles must be used to solve stoichiometry problems.145) Find the limiting reagent first. Assume that the other reactant is in excess when you calculate the moles of product formed from the first reactant. The reactant that gives the smaller amount of product is limiting. It gives the maximum amount of product for the reaction. Set up mole ratios and make them equal to each other.

This means that chlorine is limiting.

146) In a reaction that goes to completion, a limiting reactant is used up, and an excess reactant is not used up.147) H is the energy that is released in a reaction, and it is proportional to the reactants. These proportions can be used as conversion factors in stoichiometry.148) 3.90 mol H2SO4

149) 34.8 g NaOH

150) First find the theoretical yield:

151)