Q: Which of the following is the SI unit for pressure, and what is its definition in terms of force and area?

Pascal (Pa); $$1\ \text{Pa} = 1\ \text{N}/\text{m}^2$$

Q: Which of the following is the correct formula for Dalton’s Law of Partial Pressures using fractional composition?

$$P_{\text{Gas}} = m_{\text{Gas}} \cdot P_{\text{Total}}$$

Q: A gas mixture contains 72.8% chlorine and 27.2% neon by mass. If the total pressure is 809 mmHg, what is the partial pressure of neon?

$$P_{\text{Ne}} = 0.272 \times 809\ \text{mmHg}$$

Question 1

Which of the following is the SI unit for pressure, and what is its definition in terms of force and area?

Accepted Answer

Pascal (Pa); $$1\ 	ext{Pa} = 1\ 	ext{N}/	ext{m}^2$$

Question 2

A gas sample is transferred from a 5.0 L container to a 10.0 L container at constant temperature and amount. What happens to the pressure?

Accepted Answer

It will decrease

Question 3

Which of the following best describes the relationship between pressure and volume according to Boyle’s Law?

Accepted Answer

They are inversely proportional

Question 4

A 10.0 L cylinder with a movable piston contains 10.0 g of xenon gas. When an additional 10.0 g of xenon gas is added, the volume increases. Which gas law explains this observation?

Accepted Answer

Avogadro’s Law

Question 5

Which of the following statements is TRUE according to the Kinetic Molecular Theory?

Accepted Answer

The collisions of particles with one another are completely elastic.

Question 6

A sealed container with a movable piston contains a gas with a pressure of 1380 torr, a volume of 820 mL, and a temperature of 31°C. What would the volume be if the new pressure is now 2.83 atm, while the temperature decreased to 25°C? (Use the combined gas law.)

Accepted Answer

$$V_2$$ = \frac{$$P_1$$ $$V_1$$ $$T_2$$}{$$P_2$$ $$T_1$$}$$

Question 7

Which of the following conditions would make a real gas behave most ideally?

Accepted Answer

Low pressure, high temperature

Question 8

A 500 mL container at a pressure of 600 mmHg contains 29.3 g nitrogen gas at 50 ºC. Which of the following is the correct set of units for the Ideal Gas Law calculation?

Accepted Answer

P in atm, V in L, n in mol, T in K

Question 9

Which of the following is the correct formula for Dalton’s Law of Partial Pressures using fractional composition?

Accepted Answer

$$P_{	ext{Gas}} = m_{	ext{Gas}} \cdot P_{	ext{Total}}$$

Question 10

At STP, what is the volume occupied by one mole of an ideal gas?

Accepted Answer

22.4 L

Question 11

A gas mixture contains 72.8% chlorine and 27.2% neon by mass. If the total pressure is 809 mmHg, what is the partial pressure of neon?

Accepted Answer

$$P_{	ext{Ne}} = 0.272 	imes 809\ 	ext{mmHg}$$

Question 12

Which of the following is NOT a postulate of the Kinetic Molecular Theory?

Accepted Answer

Gas particles exert attractive and repulsive forces on each other.

Question 13

A sample of gas initially has a volume of 900 mL at 520 K and 1.85 atm. What is the pressure if the volume decreases to 330 mL while the temperature increases to 770 K?

Accepted Answer

$$P_2$$ = \frac{$$P_1$$ $$V_1$$ $$T_2$$}{$$V_2$$ $$T_1$$}$$

Question 14

Which of the following is the correct relationship between the partial pressure of a gas and the number of moles of that gas in a mixture (at constant T and V)?

Accepted Answer

Directly proportional

Question 15

A spray can is used until all that remains is the propellant gas, which has a pressure of 1350 torr at 25 ºC. If the can is then thrown into a fire at 455 ºC, what will be the new pressure (in torr)? (Assume constant volume.)

Accepted Answer

$$P_2$$ = $$P_1$$ \frac{$$T_2$$}{$$T_1$$}$$ (with T in K)

Question 16

Which of the following is the correct formula for the Ideal Gas Law?

Accepted Answer

$$PV = nRT$$

Question 17

Which of the following statements about STP (Standard Temperature and Pressure) is correct?

Accepted Answer

STP is 0 ºC and 1 atm

Question 18

A cylinder contains 0.615 moles of gas and has a volume of 295 mL. What will its volume be if 0.103 moles of gas escape, assuming constant T and P?

Accepted Answer

$$V_2$$ = $$V_1$$ \frac{$$n_2$$}{$$n_1$$}$$

Ch.8 Gases: Properties, Laws, and Applications

Study Guide - Practice Questions

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