Q: A sample of gas has a pressure of 2.00 atm. What is this pressure in mm Hg? (1 atm = 760 mm Hg)

$$2.00 \times 760 = 1520 mm Hg$$

Q: Boyle's Law states that for a fixed amount of gas at constant temperature:

$$P \times V = \text{constant}$$

Q: Calculate the number of moles of gas in a 10.0 L container at 2.00 atm and 300 K. Use $$R = 0.0821\ L \cdot atm \cdot $$mol^{-1}$$ \cdot K$$^{-1}$$.

$$n = \frac{P V}{R T} = \frac{2.00 \times 10.0}{0.0821 \times 300} \approx 0.81$$ mol

Question 1

Which of the following best describes the property of gases that distinguishes them from solids and liquids?

Accepted Answer

Gases expand to fill the entire volume of their container.

Question 2

Pressure is defined as:

Accepted Answer

The force exerted per unit area.

Question 3

A sample of gas has a pressure of 2.00 atm. What is this pressure in mm Hg? (1 atm = 760 mm Hg)

Accepted Answer

$$2.00 	imes 760 = 1520 mm Hg$$

Question 4

Which variable does NOT directly affect the pressure of a gas in a closed container?

Accepted Answer

Color of the container

Question 5

Boyle's Law states that for a fixed amount of gas at constant temperature:

Accepted Answer

$$P 	imes V = 	ext{constant}$$

Question 6

A 2.0 L sample of gas at 1.0 atm is compressed to 1.0 L at constant temperature. What is the new pressure?

Accepted Answer

$$2.0$$ atm

Question 7

Charles’ Law relates which two variables for a fixed amount of gas at constant pressure?

Accepted Answer

Volume and temperature

Question 8

A balloon has a volume of 500 mL at 25°C. If the temperature increases to 50°C at constant pressure, what happens to the volume?

Accepted Answer

The volume increases.

Question 9

Gay-Lussac’s Law can be expressed mathematically as:

Accepted Answer

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

Question 10

Which of the following is the correct form of the Combined Gas Law?

Accepted Answer

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

Question 11

Avogadro’s Law states that:

Accepted Answer

Equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.

Question 12

Which of the following is NOT an assumption of the kinetic molecular theory for ideal gases?

Accepted Answer

Gas particles lose energy during collisions.

Question 13

What is the value of the ideal gas constant $$R in $$units of $$L \cdot atm \cdot $$mol^{-1}$$ \cdot K$$^{-1}$$?

Accepted Answer

$$0.0821$$

Question 14

Calculate the number of moles of gas in a 10.0 L container at 2.00 atm and 300 K. Use $$R = 0.0821\ L \cdot atm \cdot $$mol^{-1}$$ \cdot K$$^{-1}$$.

Accepted Answer

$$n = \frac{P V}{R T} = \frac{2.00 	imes 10.0}{0.0821 	imes 300} \approx 0.81$$ mol

Question 15

Dalton’s Law of Partial Pressures states that:

Accepted Answer

The total pressure of a mixture of gases is the sum of the partial pressures of each gas.

Question 16

A mixture contains 2.0 mol of O$$_2$$ and 3.0 mol of N$$_2 in a 10.0 L $$container at 300 K. What is the total pressure? ($$R = 0.0821\ L \cdot atm \cdot $$mol^{-1}$$ \cdot K$$^{-1}$$)

Accepted Answer

$$P = \frac{(2.0 + 3.0) 	imes 0.0821 	imes 300}{10.0} = 1.23$$ atm

Question 17

Absolute zero is defined as:

Accepted Answer

The temperature at which all molecular motion ceases.

Question 18

A scuba tank contains a mixture of gases at a total pressure of 200 atm. If the partial pressure of oxygen is 40 atm and nitrogen is 150 atm, what is the partial pressure of the remaining gases?

Accepted Answer

$$200 - (40 + 150) = 10$$ atm

Question 19

A gas occupies 3.0 L at 2.0 atm and 300 K. What will its volume be at 1.0 atm and 300 K?

Accepted Answer

$$V_2$$ = \frac{$$P_1$$ $$V_1$$}{$$P_2$$} = \frac{2.0 	imes 3.0}{1.0} = 6.0$$ L

Chapter 10: Gases – Properties, Laws, and Calculations

Study Guide - Practice Questions

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