a gas mixture contains three components: 28 g co, 2.0 g h2 and 8.0 g of o2. if the gases are at stp, what are the partial pressures of each gas? what is the total volume?

Respuesta :

Answer: 1. If temperature is constant, the relationship between pressure and volume is

a. direct

b. inverse

2. If pressure is constant, the relationship between temperature and volume is

a. direct

b. Inverse

3. One way to increase pressure on a gas is to

a. decrease temperature

b. increase volume

c. increase the number of gas particles

d. lower the kinetic energy of the gas molecules

4. How do gas particles respond to an increase in volume?

a. increase in kinetic energy and decrease in temperature

b. decrease in kinetic energy and decrease in pressure

c. increase in temperature and increase in pressure

d. increase in kinetic energy and increase in temperature

5. If pressure of a gas is increased and its volume remains constant, what will happen to its temperature?

a. increase

b. decrease

c. stay the same

6. If a gases volume is decreased and pressure is constant, its temperature will

a. increase

b. decrease

c. remain the same

7. If the temperature of a gas remains constant but pressure is decreased, the volume will

a. increase

b. decrease

c. remain the same

8. Convert 2.3 atm into mmHg.

a. 2300 mmHg

b. 1750 mmHg

c. 2.3 mmHg

d. 0.0030 mmHg

9. Convert 6.7 liters into milliliters.

a. 0.0067 mL

b. 0.0088 mL

c. 5092 mL

d. 6700 mL

Name __________________________

Date _______________ Block ______

2.3 atm 760 mmHg = 1748 mmHg so sig.fig. = 1750mmHg

1 atm

6.7 L 1000 mL = 6700 mL

1 L

10. The pressure of a gas is 750.0 torr when its volume is 400.0 mL. Calculate the pressure (in atm) if the

gas is allowed to expand to 600.0 mL at constant temperature. (760 torr = 1 atm)

a. 0.660 atm

b. 1.48 atm P1V1 =P2V2 (0.987 atm)(400.0 mL) = x (600.0 mL)

c. 500.0 atm 0.6579 atm = x

d. 1125 atm

11. The volume of a gas is increased from 150.0 mL to 350.0 mL by heating it. If the original temperature of

the gas was 25.0 °C, what will its final temperature be (in °C)?

a. 146°C

b. 10.7°C V1 = V2 150 mL = 350.0 mL x = 695.33 K - 273 = 422°C

c. 58.3°C T1 T2 298 K X

d. 422°C

e. 695°C

12. A gas exerts a pressure of one atm at standard temperature (273.0 K). What must the temperature be

adjusted to for the gas to exert a pressure of 4.00 atm? (Give your answer in °C)

a. -205°C

b. 68.3°C P1 = P2 1 atm = 4 atm x = 1092 K or 819° C

c. 819°C T1 T2 273K X

d. 1092°C

13. A quantity of gas has a volume of 250.0 liters at 17.0°C and 3.00 atm of pressure. To what volume must

the gas be increased for the gas to be under STP conditions?

a. 78.4 L d. 771 L P1V1 = P2 V2 3 atm 250.0 mL = 1 atm X

b. 88.5 L e. 797 L T1 T2 290 K 273 K

c. 706 L 706 mL = X

14. What are standard temperature and pressure conditions for gases?

a. 0°C and 0 torr

b. 0 K and 760 torr

c. -273°C and 1 atm

d. 0°C and 760 torr

e. 0°C and 1 torr

15. If the volume of a confined gas is doubled while the temperature remains constant, what change (if any)

would be observed in the pressure?

a. It would be half as large.

b. It would double.

c. It would be four times as large.

d. It would be 1/4 as large.

e. It would remain the same.

16. A given mass of gas in a rigid container is heated from 100°C to 500°C. Which of the following

responses best describes what will happen to the pressure of the gas?

a. The pressure will decrease by a factor of five.

b. The pressure will increase by a factor of five.

c. The pressure will increase by a factor of about two. (Don’t forget to convert to Kelvin)

d. The pressure will increase by a factor of about eight.

e. The pressure will increase by a factor of about twenty-five.

17. Which of the following has the most molecules? (Think PV = nRT; so n = PV n is moles

a. 1.00 L of CH4 at 0°C and 1.00 atm RT

b. 1.00 L of N2 at 0°C and 1.00 atm R and V are the same in each problem. So n = P

c. 1.00 L of O2 at 20°C and 1.00 atm T

d. 1.00 L of CO2 at 50°C and 1.25 atm

e. 1.00 L of CO at 0°C and 1.25 atm

18. Avogadro stated that equal volumes of gases under the same conditions of temperature and pressure

have equal

a. numbers of molecules.

b. numbers of grams.

c. molar masses.

d. atoms.

e. speeds.

19. What volume of CH4 at 0°C and 1.00 atm contains the same number of molecules as 0.50 L of N2

measured at 27°C and 1.50 atm?

a. 0.37 L

b. 0.46 L

c. 0.68 L

d. 0.50 L

e. 0.82 L

20. If 3.0 L of helium at 20.0°C is allowed to expand to 4.4 L, with the pressure remaining the same, what is

the new temperature?

a. 702 K

b. 430 K

c. 157 K

d. -30.0 K

e. -55 K

21. At what temperature will 41.6 grams N2 exerts a pressure of 815 torr in a 20.0 L cylinder?

a. 134 K

b. 176 K

c. 238 K

d. 337 K

e. 400 K

22. A mixture of the gases neon and krypton is in a 2.00 liter container. The partial pressure of the neon is

0.40 atm and the partial pressure of the krypton is 1.20 atm. What is the mole fraction of neon?

a. 0.20

b. 0.25

c. 0.33

d. 0.60

e. 0.80

23. Which of the following gases has the greatest density at 0°C and 1 atm?

a. N2 28 g/mol

b. 02 32 g/mol

c. F2 38 g/mol

d. Ne 20 g/mol

e. CO 28 g/mol

starting with... PV = nRT remember n = (mass / mw)

substitute and rearrange...PV = (mass/mw) RT and mass / V = mw x P / (RT)