Chemical Engineering Chapter 12 Commercial ammonia is produced by reacting

47) What volume of H2 gas at 780 mm Hg and 23 °C is required to produce 10.6 L of NH3 gas

at the same temperature and pressure using the following chemical reaction?

N2(g) + 3H2(g) 2NH3(g)

A) 15.9 L

B) 13.0 L

C) 20.0 L

D) 15.0 L

48) Propane burners are used by campers for cooking purposes while in the wild. What volume

of H2O gas is produced by the complete combustion of 1.8 L of propane (C3H8) gas? All gas

volumes are measured at the same temperature and pressure.

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

A) 1.8 L

B) 14 L

C) 7.2 L

D) 0.52 L

49) A 0.500 L cylinder contains 0.820 grams of an unknown gas. The pressure inside the

cylinder is 2.50 atmospheres at 25.0 °C. What is the identity of the unknown gas?

A) 28.0 g/mol, N2

B) 2.02 g/mol, H2

C) 16.0 g/mol, CH4

D) 38.0 g/mol, F2

50) 0.2050 g of a liquid was added to an Erlenmeyer flask. The temperature inside the flask was

35.0 °C. The volume of the flask was 125 mL. The molecular weight of the liquid was 44.0

g/mole. Calculate the pressure inside the flask.

A) 460. mmHg

B) 58.1 mmHg

C) 716 mmHg

D) 1.40 103 mmHg

51) At 150 °C and 1.00 atm, 500 mL of a vapor has a mass of 0.8365 g. What is the molecular

weight of the compound?

A) 110. g/mol

B) 116 g/mol

C) 130. g/mol

D) 58.1 g/mol

52) At STP the volume of HCl that will result from the reaction of 0.680 L of H2 and 0.750 L of

Cl2 is ________.

H2(g) + Cl2(g) 2 HCl(g)

A) 0.680 L

B) 0.750 L

C) 1.36 L

D) 0.340 L

53) Commercial ammonia is produced by reacting hydrogen gas with nitrogen gas according to

the following equation.

N2(g) + 3 H2(g) 2 NH3(g)

If 6.00 x 104 L of N2 are reacted with 1.20 x 105 L of H2, at the same temperature and pressure,

the limiting reactant is ________ and the volume of ammonia produced is ________ L.

A) N2, 3.33 x 103

B) H2, 6.00 x 103

C) N2, 8.00 x 104

D) H2, 8.00 x 104

54) The molar volume of a gas is the volume occupied at STP by ________.

A) 22,400 mL of gas

B) 760. L of gas

C) 22.4 g of gas

D) 6.02 1023 g of gas

55) At standard conditions, one mole of any gas will occupy a volume of ________.

A) 1.00 L

B) 22.4 mL

C) 22.4 L

D) 22,400 L

56) What is the volume at STP, in liters, occupied by 26.4 g of F2 gas?

A) 4.28 L

B) 15.6 L

C) 12.4 L

D) 11.8 L

57) Three 1.0 L flasks filled with H2, O2 and He, respectively, are at STP. Which of the

following statements concerning these gases is true?

A) Each flask contains the same number of atoms.

B) There are twice as many H2 or O2 molecules as there are He atoms.

C) There are twice as many He atoms as there are H2 or O2 molecules.

D) The number of H2 or O2 molecules is the same as the number of He atoms.

58) What volume is occupied by 6.21 x 1024 molecules of CO at STP?

A) 106 L

B) 22.4 L

C) 44.3 L

D) 231 L

59) A 15.0 L cylinder was filled with O2 gas at STP. Calculate the number of O2 molecules in

the cylinder.

A) 4.03 x 1023 molecules

B) 2.77 x 1022 molecules

C) 443 molecules

D) 6.59 x 1024 molecules

60) The conditions known as STP are ________.

A) 760 atm and 273 K

B) 760 mmHg and 273 oC

C) 1 atm and 273 K

D) 1 mmHg and 273 K

61) A sample of N2 gas occupies a volume of 180. mL at STP. What volume, in L, will it occupy

at 640 mmHg and 295 K?

A) 0.231 L

B) 1.45 L

C) 1.07 L

D) 0.690 L

62) Of the following gases, the one with the greatest density at STP is ________.

A) NO

B) N2

C) O2

D) CO2

63) The density of a gas is 1.34 g/L at STP. What is the mass of one mole of this gas?

A) 30.0 g

B) 28.0 g

C) 44.0 g

D) 43.9 g

64) What is the density of F2, if the temperature is 24.0 oC and the pressure is 0.986 atm?

A) 1.24 g/L

B) 1.54 g/L

C) 2.04 g/L

D) 1.96 g/L

65) Which noble gas has a density of 5.86 g/L at STP?

A) Ne

B) Ar

C) Kr

D) Xe

66) In the reaction Fe2O3 + 3 H2 2 Fe + 3 H2O how many grams of Fe2O3 must react to

produce 10.8 liters of H2O at STP?

A) 25.7 g

B) 12.6 g

C) 65.3 g

D) 648 g

67) How many grams of sodium azide, NaN3 (molar mass = 65.02) are needed to react by the

equation below in order to inflate a 66.0 L air bag with N2(g) at 294 K and 0.989 atm pressure?

2 NaN3(s) 2 Na(s) + 3 N2(g)

A) 44.2 g

B) 60.1 g

C) 95.1 g

D) 117 g

68) Electrolysis of 12.6 g of water would produce what volume of O2 gas at 640 torr and 22.0

°C?

2 H2O (l) + electricity 2 H2(g) + O2(g)

A) 101 L

B) 44.8 L

C) 22.4 L

D) 68.4 L

69) What volume of H2, in milliliters, at 21 °C and 0.998 atm can be produced from the reaction

of 2.40 grams of Zn in excess HCl?

Zn(s) + 2 HCl(aq) ZnCl2(aq) + H2(g)

A) 888 mL

B) 675 mL

C) 3350 mL

D) 1220 mL

70) The pressure exerted by a gas collected by water displacement is obtained by subtracting the

vapor pressure of H2O from the total pressure of the gas collected. This is an example of the

application of ________.

A) Avogadro’s law

B) Dalton’s law

C) Boyle’s law

D) Charles’ law

71) What is the volume occupied by a mixture of 25.7 g of NO2 and 13.9 g of SO2 at STP?

A) 11.2 L

B) 22.4 L

C) 17.4 L

D) 26.9 L

72) A mixture of 8.95 g of Cl2 and 18.0 g of NO2 and an undetermined amount of SO2 occupies

a volume of 22.4 liters at 760 mm Hg and 0 °C. How many moles of SO2 are present?

A) 1.06 moles

B) 2.77 moles

C) 0.381 moles

D) 0.483 moles

73) What is the partial pressure of N2 in a mixture of 0.36 mole N2, 0.15 mole Ne, and 0.75

mole of O2 that has a total pressure of 3.18 atm?

A) 0.29 atm

B) 0.36 atm

C) 0.65 atm

D) 0.91 atm

74) What is the total pressure in a 4.00 L flask at 298 K, that contains 2.6 moles of He, 0.80

moles of Ne, 1.6 moles of O2?

A) 2.6 atm

B) 4.9 atm

C) 31 atm

D) 25 atm

75) What is the volume percent of Ar in a 6.50 L flask that contains 0.200 mole of Ne, 0.300

mole He, 0.600 mole of Ar at STP?

A) 36.4%

B) 54.5%

C) 44.3%

D) 21.9%

76) An excimer laser contains 0.40 mole Ar and 0.60 mole F2. The total pressure inside the laser

cavity is 1.10 atm. What is the partial pressure of Ar inside the laser?

A) 0.40 atm

B) 0.44 atm

C) 0.60 atm

D) 1.0 atm

77) A sample of SO3 gas is decomposed to SO2 and O2. 2 SO3(g) 2 SO2(g) + O2(g)

If the total pressure of SO2 and O2 is 1340 torr, calculate the partial pressure of O2 in torr.

A) 1340 torr

B) 893 torr

C) 447 torr

D) 1160 torr

12.2 Short Answer

1) A gas has a volume of 225 mL at a pressure of 162.5 torr. What is the pressure (in atm) if the

volume is decreased to 45.0 mL?

2) A quantity of gas has a volume of 3560 mL at a temperature of 55 °C and a pressure of 850

torr. What is the temperature (in °C) if the volume remains unchanged but the pressure is

decreased to 0.652 atm?

3) Chlorine gas is widely used to purify municipal water supplies and to treat swimming pool

waters. Suppose that the volume of a particular sample of Cl2 is 6.18 L at 0.884 atm and 46 °C.

At what temperature (in °C will the volume be 2.00 L if the pressure is 157 kPa?

4) A sample of helium gas has a volume of 1.25 L at -125 °C and 5.00 atm. This gas is

compressed at 50.0 atm to a volume of 325 mL. What is the final temperature of the helium gas

in °C ?

5) What is the pressure exerted by 1.00 x 1020 molecules of nitrogen in a 305 mL flask at 175

°C?

6) An unknown gas with a mass of 4.52 g was found to occupy a volume of 875 mL at 1.69 atm

and 65 °C. What is the molecular weight of this gas?

7) Monochloroethylene is used to make polyvinylchloride (PVC). It has a density of 2.56 g/L at

22.8 °C and 756 mmHg. What is the molar mass of monochloroethylene?

8) What mass of NH3 gas has a volume of 16,400 mL, a pressure of 0.955 atm and a temperature

of -23 °C?

9) A mixture of 8.50 g of hydrogen and 15.0 g of helium in a 7.30 L flask is maintained at15.0

°C. What is the total pressure in the container?