Chem 1411- Quiz 5
NAME:
1) If the volume of a sample of chlorine gas is reduced by 1/3 at constant pressure, what happens to its
absolute temperature?
A) It remains constant.
B) It decreases by 1/3.
C) It triples.
D) It increases nine-fold.
E) It increases by a factor of 9
2) What is the final Celsius temperature if 6.48 L of H2 gas at 22.0 C is cooled until the volume reaches
3.77 L?
A) 24.8 C
B) 113 C
C) 205 C
D) 7.78 C
E) 101 C
3) A cylinder of oxygen gas has a pressure of 6.00 atm at 25.0 C. What is the pressure of the gas at 0.0 C?
A) 6.55 atm B) 2.40 atm
C) 15.0 atm
D) 38.9 atm
E) 5.50 atm
4) The molar volume of a gas is the volume occupied at STP by ________.
A) 1 g of gas
B) 6.02  1023 g of gas
C) 22.41 g of gas
D) 760 L of gas E) 22,400 mL of gas
5) 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
E) 23.1 L
6) What volume is occupied by 6.21  1024 molecules of CO at STP?
A) 106 L
B) 230 L
C) 44.3 L
D) 231 L
E) 90.2 L
7) The temperature, in C, occupied by 0.643 moles of O2 gas at 0.893 atm pressure and a volume of 14.7 L is
________.
A) 16 C
B) 24 C
C) 48 C
D) 318 C
E) 249 C
8) At what temperature in oC does 0.444 mole of carbon monoxide, CO, occupy 11.8 L at 889 mmHg?
A) 51 oC
B) 14oC
C) 32oC
D) 106 oC
9) A 15.0 L cylinder was filled with of O2 gas at STP. Calculate the number of O2 molecules in the cylinder.
A) 0.669 molecules
B) 6.59  1024 molecules
C) 443 molecules
D) 2.77  1022 molecules E) 4.03  1023 molecules
10) How will the pressure of a fixed sample of gas change if its volume is halved and its temperature is
quadrupled (moles of gas remain constant)?
A) The pressure will decrease by a factor of 4.
B) The pressure will increase by a factor of 4.
C) The pressure will quadruple.
D) The pressure will decrease by a factor of 8.
E) The pressure will increase by a factor of 8.
11)
Calculate the volume occupied by 35.2 g of methane gas (CH4) at 25C and 1.0 atm.
R = 0.0821 L  atm/Kmol.
A. 0.0186 L
12)
B.4.5 L
C. 11.2 L
D. 49.2 L
E. 53.7 L
Calculate the density, in g/L, of CO2 gas at 27C and 0.50 atm pressure.
A. 0.89 g/L
B. 1.12 g/L
C. 9.93 g/L
D. 46.0 g/L
E. 2.17 kg/L
13) Determine the molar mass of Freon-11 gas if a sample weighing 0.597 g occupies 100. cm3 at 95C, and 1,000.
mmHg.
A. 0.19 g/mol
14)
D. 137 g/mol
E. 384 g/mol
A 0.271 g sample of an unknown vapor occupies 294 mL at 140C and 847 mmHg. The empirical formula of
the compound is CH2. What is the molecular formula of the compound?
A. CH2
15)
B. 35.3 g/mol C. 70.9 g/mol
B. C2H4
C. C3H6
D. C4H8
E. C6H12
What volume of oxygen gas at 320 K and 680 torr will react completely with 2.50 L of NO gas at the same
temperature and pressure?
2NO(g) + O2(g)  2NO2(g)
A. 1.25 L
16)
B. 2.50 L
C. 3.00 L
D. 1.00 L
E. 5.00 L
How many liters of chlorine gas at 25C and 0.950 atm can be produced by the reaction of 12.0 g of MnO 2?
MnO2(s) + 4HCl(aq)  MnCl2(aq) + 2H2O(l) + Cl2(g)
A. 5.36  10-3 L
17)
B. 3.64 g/mol
B.301 mmHg
E. 3.55 L
C. 78.2 g/mol
D. 137 g/mol
E. 365 g/mol
C. 356 mmHg
D. 5,345 mmHg
E. 8,020 mmHg
0.500 mole of ammonia (NH3) occupies a 1.2 L flask at 150C. Calculate the pressure of the ammonia inside
the flask.
A. 6.91  10-2 atm
20)
D. 3.09 L
A mixture of three gases has a total pressure of 1,380 mmHg at 298 K. The mixture is analyzed and is found
to contain 1.27 mol CO2, 3.04 mol CO, and 1.50 mol Ar. What is the partial pressure of Ar?
A. 0.258 atm
19)
C. 0.282 L
What is the molar mass of Freon-11 gas if its density is 6.13 g/L at STP?
A. 0.274 g/mol
18)
B. 0.138 L
B. 5.13 atm
C. 12.2 atm
D. 14.5 atm
E.22.4 atm
Calculate the number of kilograms of helium needed to inflate a balloon to a volume of 100,000 L at an
atmospheric pressure of 250 mmHg and a temperature of -35C.
A. 1.68 kg
B. 3.36 kg
C. 5.21 kg
D. 6.74 kg
E. 5120 kg