CHE 105 Spring 2020 Exam 2

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Question #: 1

Which image represents a molecular element?

A.

B.

C.

D.

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Question #: 2

Which compound contains both ionic bonds and covalent bonds?

A. C 8 H18

B. GeO2

C. FeBr3

D. K2CO3

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Question #: 3

Which is not an empirical formula?

A. C5H12

B. K2Cr2O7

C. C6H10O3

D. H2C2O4

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Question #: 4

What is the chemical formula for sodium nitrate?

A. Na3N

B. Na(NO2)2

C. NaNO3

D. Na2NO3

E. Na(NO3)2

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Question #: 5

What is the chemical formula of nickel(II) hydroxide?

A. Ni2(OH)3

B. Ni(OH)2

C. Ni2O3

D. Ni2(H2O)2

E. NiOH

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Question #: 6

What is the chemical name of N2O5? .

A. dinitrogen pentoxide

B. nitrogen(V) oxide

C. nitrogen oxide

D. nitrous pentaoxide

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Question #: 7

How many total atoms are in 7.30 g of CH4? .

A. 4.11 × 1025 atoms

B. 7.30 × 1023 atoms

C. 1.61 × 1023 atoms

D. 1.37 × 1024 atoms

E. 9.73 × 1023 atoms

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Question #: 8

How many molecules are in 1 cup (227 g) of water?

A. 6.52×10–21 molecules

B. 7.59×1024 molecules

C. 3.08×1018 molecules

D. 4.10×1026 molecules

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Question #: 9

Liquid hexane, C6H14 (molar mass = 86.178 g/mol), has a density of 0.6548 g/mL at room temperature. What volume of hexane contains 5.33 × 1022 molecules? .

A. 8.59 mL

B. 13.5 mL

C. 11.6 mL

D. 7.40 mL

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Question #: 10

A compound contains 52.14% carbon, 34.73% oxygen, and hydrogen. What is the empirical formula of the compound?

A. CHO

B. CH3O

C. C4H13O3

D. C2H6O

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Question #: 11

If the empirical formula of a compound is C9H18O and its molar mass is 284.5 g/mol, what is its molecular formula? .

A. C10H6O

B. C16H28O4

C. C20H12O2

D. C18H36O2

E. C36H72O4

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Question #: 12

How many grams of NaOH are required to make 250. mL of a 3.00 M solution?

A. 30.0 g

B. 2.78 g

C. 10.2 g

D. 13.3 g

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Question #: 13

What volume of a 0.33 M aqueous solution of C12H22O11 can be diluted with water to prepare 25 mL of a 0.025 M solution? .

A. 1.9 mL

B. 7.7 mL

C. 17 mL

D. 41 mL

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Question #: 14

What are the coefficients of the balanced equation when balanced with the smallest possible whole numbers? 1 NH3 + 2 O2 → 3 NO + 4 H2O Enter your responses as whole numbers.

1.

2.

3.

4.

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Question #: 15

Which one is a weak electrolyte in aqueous solution?

A. H2SO4

B. N2

C. NaCl

D. HC2H3O2 (acetic acid)

E. C6H12O6 (glucose)

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Question #: 16

Which pair of aqueous solutions will form a precipitate when mixed?

A. NaCl and KOH

B. LiCO3 and AgNO3

C. NH4Cl and CuSO4

D. Hg2(ClO4)2 and Pb(CH3COO)2

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Question #: 17

In the reaction of lithium hydroxide with hydrochloric acid, which two are the spectator ions?

A. Li+(aq)

B. H+(aq)

C. Cl–(aq)

D. OH–(aq)

E. H2O(l)

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Question #: 18

Which one is an acid-base reaction?

A. Zn(s) + 2 AgClO3(aq) →Zn(ClO3)2(aq) + 2 Ag(s)

B. CuBr2(aq) + 2 NH4OH(aq) →Cu(OH)2(s) +2 NH4Br(aq)

C. NaCl(aq) + LiBr(aq) →NaBr(aq) + LiCl(aq)

D. H2SO4(aq) + Ba(OH)2(aq) →BaSO4(s) + 2 H2O(l)

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Question #: 19

What is the reducing agent in the reaction shown below? Cd + NiO2 + 2 H2O → Cd(OH)2 + Ni(OH)2 .

A. Cd

B. NiO2

C. H2O

D. Cd(OH)2

E. Ni(OH)2

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Question #: 20

What is the oxidation state of carbon in HCO3–? .

A. –2

B. +6

C. +4

D. –1

E. +2

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Question #: 21

If 2.46 moles of H2O are produced in the complete reaction of Al(OH)3 with HCl, how many moles of AlCl3 are also produced? 3 HCl(aq) + Al(OH)3(s) →3 H2O(l) + AlCl3(aq) .

A. 0.66 mol AlCl3

B. 0.82 mol AlCl3

C. 1.23 mol AlCl3

D. 2.46 mol AlCl3

E. 6.92 mol AlCl3

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Question #: 22

How many grams of Li are required to produce 20.9 g of Li3N (molar mass = 34.83 g/mol) in the presence of excess oxygen according to the reaction below? 6 Li(s) + N2(g) →2 Li3N(s) .

A. 12.5 g

B. 31.6 g

C. 2.44 g

D. 8.97 g

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Question #: 23

What is the limiting reactant when 27.0 g of P and 68.0 g of I2 react according to the chemical equation below? 2 P(s) + 3 I2(s) →2 PI3(s) .

A. P(s)

B. I2(s)

C. PI3(s)

D. There is no limiting reactant is this case.

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Question #: 24

How many moles of chromium are produced by the reaction of 40.0 g of Cr2O3 (molar mass = 151.989 g/mol) with 8.00 g of aluminum? 2 Al + Cr2O3 → Al2O3 + 2 Cr .

A. 0.388 mol Cr

B. 1.24 mol Cr

C. 0.296 mol Cr

D. 0.773 mol Cr

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Question #: 25

What is the percent yield of O2 in the decomposition of 126 g of KClO3 (molar mass = 122.55 g/mol) if 32.0 g of O2 are recovered? 2 KClO3(s) →2 KCl(s) + 3 O2(g) .

A. 78.2%

B. 64.8%

C. 90.1%

D. 83.7%

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Question #: 26

In a titration, 34.62 mL of 0.1510 M NaOH are needed to neutralize 50.0 mL of an H2SO4 solution. What is the concentration of the sulfuric acid solution? .

A. 0.0229 M H2SO4

B. 0.281 M H2SO4

C. 0.0523 M H2SO4

D. 0.105 M H2SO4

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Question #: 27

Which statement is false?

A. Thermal energy is a type of kinetic energy.

B. Potential energy is stored energy.

C. Energy cannot be converted from potential to kinetic energy.

D. Energy can be neither created nor destroyed in a process.

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Question #: 28

Which one is a state function?

A. distance traveled

B. change in internal energy

C. heat

D. pressure-volume work

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Question #: 29

What is the change in the internal energy (ΔU) of a thermodynamic system if 1200 J of work is done on the system and it releases 31.0 kJ of heat to its surroundings?

A. +31.0 kJ

B. –29.8 kJ

C. +32.2 kJ

D. –1.2 kJ

E. ΔU is unchanged.

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Question #: 30

In the process of producing a silver dollar coin containing 31.1 g of pure silver, the metal is heated to 962°C. How much heat must be given off for the coin to return to room temperature, 20.0°C? The specific heat of silver is 0.24 J/g·°C.

A. 85 kJ

B. 2.4 kJ

C. 7.0 kJ

D. 31 kJ

DRAFTDo Not Use Until Posted.

CHE 105 Spring 2020 Exam 2 - Confidential

Your Name: Your ID:

attachment_for_pubExamUID_lnxp115832725516024820XX_462.jpg

Question #: 1

Which image represents a molecular element?

✓A.

B.

C.

D.

Question #: 2

Which compound contains both ionic bonds and covalent bonds?

A. C 8 H18  B. GeO2 C. FeBr3

✓D. K2CO3

Question #: 3

Which is not an empirical formula?

A. C5H12 B. K2Cr2O7 C. C6H10O3

✓D. H2C2O4

Question #: 4

What is the chemical formula for sodium nitrate?

A. Na3N B. Na(NO2)2

✓C. NaNO3 D. Na2NO3 E. Na(NO3)2

Question #: 5

What is the chemical formula of nickel(II) hydroxide?

A. Ni2(OH)3

✓B. Ni(OH)2 C. Ni2O3 D. Ni2(H2O)2 E. NiOH

Question #: 6

What is the chemical name of N2O5?

.

✓A. dinitrogen pentoxide

B. nitrogen(V) oxide C. nitrogen oxide D. nitrous pentaoxide

Question #: 7

How many total atoms are in 7.30 g of CH4?

.

A. 4.11 × 1025 atoms B. 7.30 × 1023 atoms C. 1.61 × 1023 atoms

✓D. 1.37 × 1024 atoms E. 9.73 × 1023 atoms

Question #: 8

How many molecules are in 1 cup (227 g) of water?

A. 6.52×10–21 molecules

✓B. 7.59×1024 molecules C. 3.08×1018 molecules D. 4.10×1026 molecules

Question #: 9

Liquid hexane, C6H14 (molar mass = 86.178 g/mol), has a density of 0.6548 g/mL at room

temperature.  What volume of hexane contains 5.33 × 1022 molecules?

.

A. 8.59 mL B. 13.5 mL

✓C. 11.6 mL D. 7.40 mL

Question #: 10

A compound contains 52.14% carbon, 34.73% oxygen, and hydrogen.

What is the empirical formula of the compound?

A. CHO B. CH3O C. C4H13O3

✓D. C2H6O

Question #: 11

If the empirical formula of a compound is C9H18O and its molar mass is 284.5 g/mol, what is its

molecular formula?

.

A. C10H6O B. C16H28O4 C. C20H12O2

✓D. C18H36O2 E. C36H72O4

Question #: 12

How many grams of NaOH are required to make 250. mL of a 3.00 M solution?

✓A. 30.0 g

B. 2.78 g C. 10.2 g D. 13.3 g

Question #: 13

What volume of a 0.33 M aqueous solution of C12H22O11 can be diluted with water to prepare

25 mL of a 0.025 M solution?

.

✓A. 1.9 mL

B. 7.7 mL

C. 17 mL D. 41 mL

Question #: 14

What are the coefficients of the balanced equation when balanced with the smallest possible

whole numbers?

    1     NH3 +     2     O2 →    3     NO +     4     H2O

Enter your responses as whole numbers.

1. 4

2. 5

3. 4

4. 6

Question #: 15

Which one is a weak electrolyte in aqueous solution?

A. H2SO4 B. N2 C. NaCl

✓D. HC2

H3

O2

(acetic acid) E. C6H12O6 (glucose)

Question #: 16

Which pair of aqueous solutions will form a precipitate when mixed?

A. NaCl and KOH

✓B. LiCO3 and AgNO3 C. NH4Cl and CuSO4 D. Hg2(ClO4)2 and Pb(CH3COO)2

Question #: 17

In the reaction of lithium hydroxide with hydrochloric acid, which two are the spectator ions?

✓A. Li+(aq)

B. H+(aq) ✓C. Cl–(aq)

D. OH–(aq) E. H2O(l)

Question #: 18

Which one is an acid-base reaction?

A. Zn(s) + 2 AgClO3(aq) →Zn(ClO3)2(aq) + 2 Ag(s) B. CuBr

2(aq) + 2 NH

4OH(aq) →Cu(OH)

2(s) +2 NH

4Br(aq)

C. NaCl(aq) + LiBr(aq) →NaBr(aq) + LiCl(aq) ✓D. H2SO4(aq) + Ba(OH)2(aq) →BaSO4(s) + 2 H2O(l)

Question #: 19

What is the reducing agent in the reaction shown below?

Cd + NiO2 + 2 H2O → Cd(OH)2 + Ni(OH)2

.

✓A. Cd B. NiO2 C. H2O D. Cd(OH)2 E. Ni(OH)2

Question #: 20

What is the oxidation state of carbon in HCO3–?

.

A. –2 B. +6

✓C. +4 D. –1 E. +2

Question #: 21

If 2.46 moles of H2O are produced in the complete reaction of Al(OH)3 with HCl, how many

moles of AlCl3 are also produced?

3 HCl(aq) + Al(OH)3(s) →3 H2O(l) + AlCl3(aq)

.

A. 0.66 mol AlCl3

✓B. 0.82 mol AlCl3 C. 1.23 mol AlCl3 D. 2.46 mol AlCl3 E. 6.92 mol AlCl3

Question #: 22

How many grams of Li are required to produce 20.9 g of Li3N (molar mass = 34.83 g/mol) in the

presence of excess oxygen according to the reaction below?

6 Li(s) + N2(g) →2 Li3N(s)

.

✓A. 12.5 g

B. 31.6 g C. 2.44 g D. 8.97 g

Question #: 23

What is the limiting reactant when 27.0 g of P and 68.0 g of I2 react according to the chemical

equation below?

2 P(s) + 3 I2(s) →2 PI3(s)

.

A. P(s)

✓B. I2(s) C. PI3(s) D. There is no limiting reactant is this case.

Question #: 24

How many moles of chromium are produced by the reaction of 40.0 g of Cr2O3 (molar mass =

151.989 g/mol) with 8.00 g of aluminum?

2 Al + Cr2O3 → Al2O3 + 2 Cr

.

A. 0.388 mol Cr B. 1.24 mol Cr

✓C. 0.296 mol Cr D. 0.773 mol Cr

Question #: 25

What is the percent yield of O2 in the decomposition of 126 g of KClO3 (molar mass = 122.55

g/mol) if 32.0 g of O2 are recovered?

2 KClO3(s) →2 KCl(s) + 3 O2(g)

.

A. 78.2%

✓B. 64.8% C. 90.1% D. 83.7%

Question #: 26

In a titration, 34.62 mL of 0.1510 M NaOH are needed to neutralize 50.0 mL of an H2SO4solution.  What is the concentration of the sulfuric acid solution?

.

A. 0.0229 M H2SO4 B. 0.281 M H2SO4

✓C. 0.0523 M H2SO4 D. 0.105 M H2SO4

Question #: 27

Which statement is false?

A. Thermal energy is a type of kinetic energy. B. Potential energy is stored energy.

✓C. Energy cannot be converted from potential to kinetic energy. D. Energy can be neither created nor destroyed in a process.

Question #: 28

Which one is a state function?

A. distance traveled

✓B. change in internal energy C. heat D. pressure-volume work

Question #: 29

What is the change in the internal energy (ΔU) of a thermodynamic system if 1200 J of work is

done on the system and it releases 31.0 kJ of heat to its surroundings? 

A. +31.0 kJ

✓B. –29.8 kJ C. +32.2 kJ D. –1.2 kJ E. ΔU is unchanged.

Question #: 30

In the process of producing a silver dollar coin containing 31.1 g of pure silver, the metal is

heated to 962°C.  How much heat must be given off for the coin to return to room temperature,

20.0°C?  The specific heat of silver is 0.24 J/g·°C.

A. 85 kJ B. 2.4 kJ

✓C. 7.0 kJ D. 31 kJ