1. University of Kentucky
Clicker Questions
Chapter 5
Gases
Allison Soult
University of Kentucky

2. A chamber has a pressure of 1. 5 atm at a volume of 1. 4 L
A chamber has a pressure of 1.5 atm at a volume of 1.4 L. What is the pressure when the piston compresses the sample to a volume of 0.60 L?
3.5 L
0.64 L
1.8 L
1.6 L
0.29 L
Answer: a

3. Not enough information
The volume of O2 gas in a balloon at 1.0 atm and 305 K is 0.65 L. Calculate the volume of the gas after the temperature is lowered to 77 K while keeping the pressure and amount of O2 constant.
0.16 L
0.65 L
2.8 × 10–5 L
3.6 × 104 L
Not enough information
Answer: a

4. How many moles of helium are found in a balloon that contains 5
How many moles of helium are found in a balloon that contains 5.5 L of helium at a pressure of 1.15 atm and a temperature of 22.0 ºC?
3.5
0.26
2.6
0.35
3.8
Answer: b

5. A 0. 49 mol sample of oxygen is in a 4. 8 L container at 25 ºC
A 0.49 mol sample of oxygen is in a 4.8 L container at 25 ºC. What is the pressure in the container?
254 atm
8.6 atm
2.5 atm
0.40 atm
Answer: c

6. Which of the following will have the greatest volume at STP?
5.0 g H2
5.0 g N2
5.0 g O2
5.0 g CO
All of the above have the same volume.
Answer: a

7. All have the same density N2 O2 Ar CO2
The four most common gases in the atmosphere are N2, O2, Ar, and CO2. Assuming all gases are in containers of equal size, temperature, and pressure, which gas has the highest density?
All have the same density N2 O2 Ar
CO2
Answer: e

8. A 3. 50 g sample of a diatomic gas in a 1
A 3.50 g sample of a diatomic gas in a 1.5 L container has a pressure of 2.42 atm at 355 K. Determine the identity of the gas. H2 N2
Cl2 O2 F2
Answer: b

9. What is the partial pressure of oxygen in a mixture that contains 0
What is the partial pressure of oxygen in a mixture that contains 0.30 moles of O2, 0.70 moles of N2, and 0.25 moles of Ar with a total pressure of 1.1 atm?
0.33 atm
0.26 atm
0.35 atm
0.30 atm
0.80 atm
Answer: b

10. A gas phase mixture of H2 and N2 has a total pressure of 784 torr with an H2 partial pressure of 124 torr. What mass of N2 gas is present in 2.00 L of the mixture at 298 K? g g
0.374 g
0.994 g
1.99 g
Answer: e

11. Acetylene may be produced from the reaction between calcium carbide and water. How many moles of acetylene are present in a mL sample of gas collected over water at 20.0 ºC and a total pressure of 758 torr? The vapor pressure of water at 20.0 ºC is mm Hg.
0.0207
0.0203
15.4
0.297
0.304
Answer: b

12. What mass of water vapor is produced from the gas phase reaction of O2 with H2 in a 2.5 L container at 28 ºC if the partial pressures of O2 and H2 are PO2 = 0.98 atm and PH2 = 1.24 atm? 2 H2 (g)+ O2 (g)→ 2 H2O (g)
1.79 g
2.25 g
3.57 g
4.51 g
5.82 g
Answer: b

13. All have the same average kinetic energy.
The four most common gases in the atmosphere are N2, O2, Ar, and CO2. Which gas has the highest average kinetic energy at room temperature? N2 O2 Ar
CO2
All have the same average kinetic energy.
Answer: e

14. Which of the following will have the greatest root-mean-square velocity at 300 K?
CO2
SO2
Answer: a

15. A has the same molar mass of B.
The rate of effusion of A is four times the rate of B. Which best describes the ratio of their molar masses?
A has the same molar mass of B.
The molar mass of B is twice that of A.
The molar mass of B is four times that of A.
The molar mass of B is sixteen times that of A.
Answer: d

16. Under what conditions would Cl2 gas be the least ideal?
High pressure and low temperature
High pressure and high temperature
Low pressure and high temperature
Low pressure and low temperature
Answer: a