Question 1

A hot air balloon rises because the air inside the balloon is heated. Which gas law best explains why the balloon expands as it is heated, and what is the mathematical relationship?

Accepted Answer

Charles’s Law: $$\frac{V_1$}{T_1$} = \frac{V_2$}{T_2$}$$

Question 2

A barometer is used to measure atmospheric pressure. If the height of the mercury column is 760 mm, what is the atmospheric pressure in atm?

Accepted Answer

$$1.00$$ atm

Question 3

A student collects a gas in an open-end manometer. The mercury in the arm open to the air is 80 mm higher than the arm connected to the gas, and the atmospheric pressure is 740 torr. What is the pressure of the gas in torr?

Accepted Answer

$$820$$ torr

Question 4

Which of the following best describes why gases are compressible?

Accepted Answer

Gas particles have negligible volume compared to the container.

Question 5

A 2.0 L sample of gas at 1.5 atm is compressed to 1.0 L at constant temperature. What is the final pressure?

Accepted Answer

$$3.0$$ atm

Question 6

A gas occupies 5.0 L at 27°C. What volume will it occupy at 127°C, assuming constant pressure?

Accepted Answer

$$6.67 L$$

Question 7

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

Accepted Answer

Gas particles exert attractive and repulsive forces on each other.

Question 8

A scuba tank contains a mixture of helium and oxygen. If the partial pressure of helium is 8.0 atm and oxygen is 2.0 atm, what is the total pressure?

Accepted Answer

$$10.0$$ atm

Question 9

Which of the following gases will effuse the fastest under identical conditions?

Accepted Answer

H$$_2$$

Question 10

A 0.50 L breath of air at 1.0 atm and 37°C is taken. How many moles of air are inhaled? ($$R = 0.0821 L$$·atm/mol·K)

Accepted Answer

$$0.020$$ mol

Question 11

A gas has a density of 1.18 g/L at 25°C and 1 atm. What is its molar mass? ($$R = 0.0821 L$$·atm/mol·K)

Accepted Answer

$$28.9 g/$$mol

Question 12

Which of the following best explains why real gases deviate from ideal behavior at high pressures?

Accepted Answer

The volume of gas particles becomes significant compared to the container.

Question 13

According to Graham’s Law, what is the ratio of the rate of effusion of H$$_2 ($$molar mass = 2.0 g/mol) to O$$_2 ($$molar mass = 32.0 g/mol)?

Accepted Answer

$$8.0$$

Question 14

A mixture contains 2.0 mol N$$_2$$ and 3.0 mol O$$_2. If $$the total pressure is 5.0 atm, what is the partial pressure of O$$_2$$?

Accepted Answer

$$3.0$$ atm

Question 15

Which of the following changes will increase the pressure of a fixed amount of gas in a rigid container?

Accepted Answer

Increasing the temperature

Question 16

A 250 mL bulb is filled with CO$$_2 at 738 $$torr and 23°C. How many moles of CO$$_2$$ are present? ($$R = 0.0821 L$$·atm/mol·K)

Accepted Answer

$$0.009997$$ mol

Question 17

Which of the following is a correct statement about the kinetic energy of gas particles?

Accepted Answer

At the same temperature, all gases have the same average kinetic energy.

Question 18

Which equation is used to correct for the non-ideal behavior of real gases?

Accepted Answer

$$\left(P + \frac{n^2$a}{V^2$}\right)(V - nb) = nRT$$

Question 19

A sample of exhaled air contains N$$_2 (563 $$mmHg), O$$_2 (118 $$mmHg), CO$$_2 (30 $$mmHg), and H$$_2O (50 $$mmHg). What is the total pressure?

Accepted Answer

$$761$$ mmHg

Chapter 6: Gases – Properties, Laws, and Applications

Guida di studio - Domande di pratica

Study guide - Flashcard