Chapter 3 2 When the following equation is balanced, the coefficient

19) When the following equation is balanced, the coefficient of dinitrogen pentoxide is ________.

N2O5 (g) + H2O (l) → HNO3 (aq)

A) 1

B) 2

C) 3

D) 4

E) 5

20) When the following equation is balanced, the coefficient of water is ________.

N2O5 (g) + H2O (l) → HNO3 (aq)

A) 5

B) 2

C) 3

D) 4

E) 1

21) When the following equation is balanced, the coefficient of nitric acid is ________.

N2O5 (g) + H2O (l) → HNO3 (aq)

A) 5

B) 2

C) 3

D) 4

E) 1

22) Write the balanced equation for the reaction that occurs when methanol, CH3OH (l), is burned in air.

What is the coefficient of methanol in the balanced equation?

A) 1

B) 2

C) 3

D) 4

E) 3/2

23) Write the balanced equation for the reaction that occurs when methanol, CH3OH (l), is burned in air.

What is the coefficient of oxygen in the balanced equation?

A) 1

B) 2

C) 3

D) 4

E) 3/2

24) What is the coefficient of O2 when the following equation is completed and balanced?

C4H8O2 + O2 → ________

A) 2

B) 3

C) 5

D) 6

E) 1

25) Predict the product in the combination reaction below.

Al (s) + N2 (g) → ________

A) AlN

B) Al3N

C) AlN2

D) Al3N2

E) AlN3

26) The balanced equation for the decomposition of sodium azide is ________.

A) 2NaN3 (s) → 2Na (s) + 3N2 (g)

B) 2NaN3 (s) → Na2 (s) + 3N2 (g)

C) NaN3 (s) → Na (s) + N2 (g)

D) NaN3 (s) → Na (s) + N2 (g) + N (g)

E) 2NaN3 (s) → 2Na (s) + 2N2 (g)

27) There are ________ mol of carbon atoms in 4 mol of C4H8O2.

A) 4

B) 8

C) 16

D) 20

E) 32

28) There are ________ sulfur atoms in 25 molecules of C4H4S2.

A) 1.5 × 1025

B) 4.8 × 1025

C) 3.0 × 1025

D) 50

E) 6.02 × 1023

29) There are ________ hydrogen atoms in 25 molecules of C4H4S2.

A) 25

B) 3.8 × 1024

C) 6.0 × 1025

D) 100

E) 1.5 × 1025

30) A sample of C3H8O that contains 200 molecules contains ________ carbon atoms.

A) 600

B) 200

C) 3.61 × 1026

D) 1.20 × 1026

E) 4.01 × 1025

31) How many moles of carbon monoxide are there in 36.55 g of carbon monoxide?

A) 0.8452

B) 1.305

C) 0.9291

D) 2.589

E) 3.046

32) How many moles of carbon dioxide are there in 52.06 g of carbon dioxide?

A) 0.8452

B) 1.183

C) 6.022 × 1023

D) 8.648 × 1023

E) 3.134 × 1025

33) There are ________ molecules of methane in 0.123 mol of methane (CH4).

A) 5

B) 2.46 × 10-2

C) 2.04 × 10–25

D) 7.40 × 1022

E) 0.615

34) What is the empirical formula of a compound that contains 27.0% S, 13.4% O, and 59.6% Cl by mass?

A) SOCl

B) SOCl2

C) S2OCl

D) SO2Cl

E) ClSO4

35) What is the empirical formula of a compound that contains 29% Na, 41% S, and 30% O by mass?

A) Na2S2O3

B) NaSO2

C) NaSO

D) NaSO3

E) Na2S2O6

36) What is the empirical formula of a compound that contains 49.4% K, 20.3% S, and 30.3% O by mass?

A) KSO2

B) KSO3

C) K2SO4

D) K2SO3

E) KSO4

37) A compound contains 40.0% C, 6.71% H, and 53.29% O by mass. The molecular weight of the

compound is 60.05 amu. The molecular formula of this compound is ________.

A) C2H4O2

B) CH2O

C) C2H3O4

D) C2H2O4

E) CHO2

38) A compound that is composed of carbon, hydrogen, and oxygen contains 70.6% C, 5.9% H, and 23.5%

O by mass. The molecular weight of the compound is 136 amu. What is the molecular formula?

A) C8H8O2

B) C8H4O

C) C4H4O

D) C9H12O

E) C5H6O2

39) A compound that is composed of only carbon and hydrogen contains 85.7% C and 14.3% H by mass.

What is the empirical formula of the compound?

A) CH2

B) C2H4

C) CH4

D) C4H8

E) C86H14

40) A compound that is composed of only carbon and hydrogen contains 80.0% C and 20.0% H by mass.

What is the empirical formula of the compound?

A) C20H60

B) C7H20

C) CH3

D) C2H6

E) CH4

41) A compound contains 38.7% K, 13.9% N, and 47.4% O by mass. What is the empirical formula of the

compound?

A) KNO3

B) K2N2O3

C) KNO2

D) K2NO3

E) K4NO5

42) A compound is composed of only C, H, and O. The combustion of a 0.519–g sample of the compound

yields 1.24 g of CO2 and 0.255 g of H2O. What is the empirical formula of the compound?

A) C6H6O

B) C3H3O

C) CH3O

D) C2H6O5

E) C2H6O2

43) Combustion of a 1.031-g sample of a compound containing only carbon, hydrogen, and oxygen

produced 2.265 g of CO2 and 1.236 g of H2O. What is the empirical formula of the compound?

A) C3H8O

B) C3H5O

C) C6H16O2

D) C3H9O3

E) C3H6O3

44) Combustion of a 0.9827-g sample of a compound containing only carbon, hydrogen, and oxygen

produced 1.900 g of CO2 and 1.070 g of H2O. What is the empirical formula of the compound?

A) C2H5O

B) C4H10O2

C) C4H11O2

D) C4H10O

E) C2H5O2

45) The combustion of ammonia in the presence of excess oxygen yields NO2 and H2O:

4 NH3 (g) + 7 O2 (g) → 4 NO2 (g) + 6 H2O (g)

The combustion of 43.9 g of ammonia produces ________ g of NO2.

A) 2.58

B) 178

C) 119

D) 0.954

E) 43.9

46) The combustion of propane (C3H8) in the presence of excess oxygen yields CO2 and H2O:

C3H8 (g) + 5O2 (g) → 3CO2 (g) + 4H2O (g)

When 2.5 mol of O2 are consumed in their reaction, ________ mol of CO2 are produced.

A) 1.5

B) 3.0

C) 5.0

D) 6.0

E) 2.5

47) Calcium carbide (CaC2) reacts with water to produce acetylene (C2H2):

CaC2 (s) + 2H2O (g) → Ca(OH)2 (s) + C2H2 (g)

Production of 13 g of C2H2 requires consumption of ________ g of H2O.

A) 4.5

B) 9.0

C) 18

D) 4.8 × 102

E) 4.8 × 10-2

30

48) Calcium carbide (CaC2) reacts with water to produce acetylene (C2H2):

CaC2 (s) + 2H2O (g) → Ca(OH)2 (s) + C2H2 (g)

The complete reaction of 57.4 g of CaC2 requires consumption of ________ g of H2O.

A) 0.895

B) 64.1

C) 32.3

D) 1.79

E) 18.0

49) Under appropriate conditions, nitrogen and hydrogen undergo a combination reaction to yield

ammonia:

N2 (g) + 3H2 (g) → 2NH3 (g)

A 7.1-g sample of N2 requires ________ g of H2 for complete reaction.

A) 0.51

B) 0.76

C) 1.2

D) 1.5

E) 17.2

50) Under appropriate conditions, nitrogen and hydrogen undergo a combination reaction to yield

ammonia:

N2 (g) + 3H2 (g) → 2NH3 (g)

A ________ g sample of N2 requires 3.0 g of H2 for complete reaction.

A) 0.51

B) 0.76

C) 1.2

D) 14.0

E) 17.2

51) Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide:

PbCO3 (s) → PbO (s) + CO2 (g)

How many grams of lead (II) oxide will be produced by the decomposition of 2.50 g of lead (II)

carbonate?

A) 0.41

B) 2.50

C) 0.00936

D) 2.09

E) 2.61

52) The combustion of propane (C3H8) produces CO2 and H2O:

C3H8 (g) + 5O2 (g) → 3CO2 (g) + 4H2O (g)

The reaction of 2.5 mol of O2 with 4.6 mol of C3H8 will produce ________ mol of H2O.

A) 4.0

B) 3.0

C) 2.5

D) 2.0

E) 1.0

53) GeF3H is formed from GeH4 and GeF4 in the combination reaction:

GeH4 + 3GeF4 → 4GeF3H

If the reaction yield is 92.6%, how many moles of GeF4 are needed to produce 8.00 mol of GeF3H?

A) 3.24

B) 5.56

C) 6.48

D) 2.78

E) 2.16

32

54) Under appropriate conditions, nitrogen and hydrogen undergo a combination reaction to yield

ammonia:

N2 (g) + 3H2 (g) → 2NH3 (g)

If the reaction yield is 87.5%, how many moles of N2 are needed to produce 3.00 mol of NH3?

A) 0.166

B) 1.00

C) 1.5

D) 1.71

E) 2.32

55) Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide:

PbCO3 (s) → PbO (s) + CO2 (g)

If the reaction yield is 95.7%, how many grams of lead (II) oxide will be produced by the decomposition

of 2.50 g of lead (II) carbonate?

A) 1.04

B) 1.55

C) 2.18

D) 4.00

E) 5.55

56) The combustion of ammonia in the presence of oxygen yields NO2 and H2O:

4 NH3 (g) + 7O2 (g) → 4 NO2 (g) + 6 H2O (g)

The combustion of 43.9 g of ammonia with 258 g of oxygen produces ________ g of NO2.

A) 212

B) 178

C) 119

D) 0.954

E) 43.9

57) What mass in grams of hydrogen is produced by the reaction of 4.73 g of magnesium with 1.83 g of

water?

Mg (s) + 2H2O (l) → Mg(OH)2 (s) + H2 (g)

A) 0.102

B) 0.0162

C) 0.0485

D) 0.219

E) 0.204

58) If the reaction yield is 94.4%, what mass in grams of hydrogen is produced by the reaction of 4.73 g of

magnesium with 1.83 g of water?

Mg (s) + 2H2O (l) → Mg(OH)2 (s) + H2 (g)

A) 0.0962

B) 0.0162

C) 0.0485

D) 0.219

E) 0.204

59) Silver nitrate and aluminum chloride react with each other by exchanging anions:

3AgNO3 (aq) + AlCl3 (aq) → Al(NO3)3 (aq) + 3AgCl (s)

What mass in grams of AgCl is produced when 4.22 g of AgNO3 react with 7.73 g of AlCl3?

A) 17.6

B) 4.22

C) 24.9

D) 3.56

E) 11.9

34

60) How many moles of magnesium oxide are produced by the reaction of 3.82 g of magnesium nitride

with 7.73 g of water?

Mg3N2 + 3H2O → 2NH3 + 3MgO

A) 0.114

B) 0.0378

C) 0.429

D) 0.0756

E) 4.57

61) A 3.82-g sample of magnesium nitride is reacted with 7.73 g of water:

Mg3N2 + 3H2O → 2NH3 + 3MgO

The yield of MgO is 3.60 g. What is the percent yield in the reaction?

A) 94.5

B) 78.4

C) 46.6

D) 49.4

E) 99.9

62) Pentacarbonyliron (Fe(CO)5) reacts with phosphorous trifluoride (PF3) and hydrogen, releasing

carbon monoxide:

Fe(CO)5 + PF3 + H2 → Fe(CO)2(PF3)2(H)2 + CO (not balanced)

The reaction of 5.0 mol of Fe(CO)5 , 8.0 mol of PF3 and 6.0 mol of H2 will release ________ mol of CO.

A) 15

B) 5.0

C) 24

D) 6.0

E) 12

63) What is the maximum mass in grams of NH3 that can be produced by the reaction of 1.0 g of N2 with

3.0 g of H2 via the equation below?

N2 (g) + H2 (g) → NH3 (g) (not balanced)

A) 2.0

B) 1.2

C) 0.61

D) 17

E) 4.0

64) What is the maximum amount in grams of SO3 that can be produced by the reaction of 1.0 g of S with

of O2 via the equation below?

S (s) + O2 (g) → SO3 (g) (not balanced)

A) 0.27

B) 1.7

C) 2.5

D) 3.8

E) 2.0

65) Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide:

4Al (s) + 3O2 (g) → 2Al2O3 (s)

The maximum amount of Al2O3 that can be produced from 2.5 g of Al and 2.5 g of O2 is ________ g.

A) 9.4

B) 7.4

C) 4.7

D) 5.3

E) 5.0

66) Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride:

S (s) + 3F2 (g) → SF6 (g)

The maximum amount of SF6 that can be produced from the reaction of 3.5 g of sulfur with 4.5 g of

fluorine is ________ g.

A) 12

B) 3.2

C) 5.8

D) 16

E) 8.0

67) Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide:

4Al (s) + 3O2 (g) → 2Al2O3 (s)

In a particular experiment, the reaction of 2.5 g of Al with 2.5 g of O2 produced 3.5 g of Al2O3. The %

yield of the reaction is ________.

A) 74

B) 37

C) 47

D) 66

E) 26

68) Sulfur and oxygen react in a combination reaction to produce sulfur trioxide, an environmental

pollutant:

2S (s) + 3O2 (g) → 2SO3 (g)

In a particular experiment, the reaction of 1.0 g S with 1.0 g O2 produced 0.80 g of SO3. The % yield in

this experiment is ________.

A) 30

B) 29

C) 21

D) 88

E) 47

69) Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride:

S (s) + 3F2 (g) → SF6 (g)

In a particular experiment, the percent yield is 79.0%. This means that in this experiment, a 7.90-g sample

of fluorine yields ________ g of SF6.

A) 30.3

B) 10.1

C) 7.99

D) 24.0

E) 0.110