Bell Work1. Convert 15.3 atm to kPa2. Convert 96.3 L of a gas at STP to moles.3. What is the temperature and pressure at STP?4. A scientist is trying to determine the pressure of a

system that is made up of 4 gases. One gas has a pressure of 20 kPa. Another gas has a pressure of 5 kPa. The remaining two gases have a pressure of 2.5 kPa. What is the total pressure?

5. A system originally has a pressure of 25.2 kPa, a volume of 15.1 L and a temperature of 45.5 ˚C. What is the new volume if the pressure is decreased to 20.0 kPa and the temperature is increased to 60 ˚C?

6. How many moles are in a system that has a pressure of 2.5 atm, a volume of 33.3 L and a temperature of 75.2 ˚C?

Homework Answers

1. 4.692. 1501 m/s3. 17.75 g/mol4. 0.485; slower5. 128 g/mol; HI6. 64 g/mol; SO2

7. 1920 m/s

Reality Check1) In comparing the rates of diffusion of CO2

with that of Kr, which gas will diffuse faster? 2) To two decimal places, what will vA/vB (treat

this as x) be equal to if CO2 is considered to be A and Kr is considered to be B.

3) What is the molar mass of a gas if it diffuses at a rate of 647 m/s while chlorine (Cl2) gas diffuses at 840 m/s at the same temperature?

After you are finished, continue working on the lab.

Unit 9 ReviewGases

The Game Board

1 2 3 4 56 7 8 9 10

11 12 13 14 1516 17 18 19 2021 22 23 24 2526 27 28 29 3031 32 33 34 35

1Calculate the approximate volume of a

2.50 mol sample of gas at -8.0°C and a pressure of 3.50 atm.

15.5 L

2In the reaction N2 (g) + 3H2 --> 2NH3

(g), the volume ratio of H2 to N2 is___________

3 to 1

3A pressure of 165 kPa is equal to

_____ atm.

1.63

4What does the constant bombardment

of gas molecules against the inside of a container cause?

Pressure

5What happens to the volume of a gas

during compression?

The Volume Decreases

6A sample of a gas has a pressure of

2.25 atm, a volume of 650 mL and a temperature of 36°C. What would the volume of the gas be if the pressure is increased to 3.20 atm and the temperature is decreased to 31°C?

449.6 mL

7What temperature is needed to

pressurize a 27.3 L container with 6.34 moles of air to 564.8 kPa?

292.5 K

8When pressure, volume, and

temperature are known, the ideal gas law can be used to calculate ______________.

Molar amount (moles)

9According to the

diagram to the right, what PV/nRT value do ideal gases have all the time?

1.0

10What is the SI unit of pressure?

Pascal

11If a gas with an odor is released in a

room, it quickly can be detected across the room because it ______________.

Diffuses

12A pressure of 355000 Pa is equal to

_____ psi.

51.5

13The principle that under similar

pressures and temperatures, equal volumes of gases contain the same number of molecules is attributed to ________________.

Avogadro

14Nitrogen reacts with hydrogen to make

ammonia [N2 (g) + 3H2 (g) --> 2NH3 (g)]. If one needs to produce 4 L of ammonia, how many liters of nitrogen are needed?

2 L

15A sample of a gas occupies a volume

of 1.1 L at 33°C. What temperature is needed to increase the volume of the gas to 1.9 L, if the pressure remains constant?

528.5 K or 255°C

16A 10.5 L sample of a gas has a mass

of 95.9 g at 7.6 atm and 35°C. What is the molar mass of the gas? (Hint: divide the given mass by n).

30.4 g/mol

17According to the

diagram to the right, at what pressure do all the gases most resemble an ideal gas?

0 atm

18A pressure of 560 mmHg is equal to

_____ kPa.

74.7

19Who is accredited with the idea that in

a reaction, two volumes of hydrogen gas will combine with one volume of oxygen gas to produce two volumes of water vapor?

Gay-Lussac

20The pressure of each gas in a mixture

is called the ____________________ pressure.

Partial

21A sample of a gas has a pressure of

567 mmHg at 23°C. What would the gas pressure be at 41°C, if the volume remains constant?

601 mmHg

22To two decimal places, what will vA/vB

be equal to if N2 is considered to be gas A and NO is considered to be gas B. (A diffusion problem)

1.03

23Standard temperature and pressure for

a gas is ____________________

0°C and 1 atm.

24The total pressure of a system of four

gases is 35 atm. The first gas has a pressure of 5 atm. The second gas has a pressure of 8 atm. The remaining two pressures are the same. What is the partial pressure of the other two gases?

11

25Charles’s law is the direct relationship

between ____________________ and volume.

Temperature

26What is the molar mass of a gas if it

diffuses at a rate of 258 m/s while Iodine gas diffuses at 125 m/s at the same temperature?

29.7 g

272H2O(l) + electricity 2H2(g) + O2(g)

What mass of H2O is needed to create 15.64 L of O2, if the temperature is 25°C and the pressure is 1.2 atm?

27.6 g

28The average kinetic energy of random

motion is proportional to the temperature in what unit?

Kelvin

29A sample of oxygen occupies 350 mL

when the pressure is 5 atm. At constant temperature, what volume does the gas occupy when pressure falls to 3 atm?

583 mL

30Who developed the concept that the

total pressure of a mixture of gases is the sum of their partial pressures?

Dalton

31What is the theory that explains that the

behavior of physical systems depends on the combined actions of the molecules constituting the system?

Kinetic Molecular Theory

32A mixture of gases with a pressure of 800.0

mm Hg contains 60% nitrogen and 40% oxygen by volume. What is the partial pressure of oxygen in this mixture?

320 mm Hg

33Line D represents water.

If the atmospheric pressure in a flask is lowered to 70 kPa, water would boil at what temperature?

92 C

34T1 = 76 C P1 = 4 atm V1 = 560 mL

T2 = 92 C P2 = 2 atm V2 = ?

1171 mL

35The rate of diffusion of a gas depends on the

____________ of the gas.

Molar Mass