Question 1

Which of the following statements about gases is CORRECT according to the kinetic molecular theory?

Accepted Answer

Gas molecules are in constant, random motion and experience elastic collisions with the walls of their container.

Question 2

A sample of gas at 1.00 atm and 22.0°C occupies 2.50 L. If the pressure is increased to 2.00 atm and the temperature is raised to 44.0°C, what is the new volume of the gas? (Assume ideal gas behavior.)

Accepted Answer

$$V_2$$ = \frac{$$P_1$$ $$V_1$$ $$T_2$$}{$$P_2$$ $$T_1$$} = \frac{(1.00\ \mathrm{atm})(2.50\ \mathrm{L})(317\ \mathrm{K})}{(2.00\ \mathrm{atm})(295\ \mathrm{K})} = 1.34\ \mathrm{L}$$

Question 3

Which of the following correctly expresses 265 Torr in both mmHg and atm?

Accepted Answer

265 mmHg and $$0.349\ \mathrm{atm}$$

Question 4

A 0.500 mol sample of $$O_2$$ gas occupies 12.0 L at a certain temperature and pressure. If all the $$O_2 is $$converted to $$O_3$$ according to $$3O_2(g) \rightarrow 2O_3(g)$$, what volume will the $$O_3$$ occupy under the same conditions?

Accepted Answer

$$V_{O_3$} = 8.00\ \mathrm{L}$$

Question 5

Which of the following best describes the relationship between pressure and volume for a fixed amount of gas at constant temperature (Boyle's Law)?

Accepted Answer

$$P \propto \frac{1}{V}$$

Question 6

A 1.00 mol sample of argon gas is at 300.0 K and 1.00 bar. What is the volume occupied by the gas? (Use $$R = 0.08314\ \mathrm{bar\ L\ $$mol^{-1}$$\ K$$^{-1}$$})$$

Accepted Answer

$$V = \frac{nRT}{P} = \frac{(1.00)(0.08314)(300.0)}{1.00} = 24.94\ \mathrm{L}$$

Question 7

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

Accepted Answer

Gas molecules experience significant attractive and repulsive forces.

Question 8

A mixture contains 6.00 g of $$O_2(g$$)$$ and 9.00 g of CH_4$(g) in a 5.00 L $$vessel at 0°C. What is the total pressure in the vessel? ($$R = 0.08206\ \mathrm{L\ atm\ $$mol^{-1}$$\ K$$^{-1}$$})$$

Accepted Answer

$$P_{total} = 3.36\ \mathrm{atm}$$

Question 9

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

Accepted Answer

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

Question 10

According to Graham's Law, if an unknown diatomic gas effuses at 0.355 times the rate of $$O_2$$ under identical conditions, what is the molar mass of the unknown gas?

Accepted Answer

$$M_{unknown} = 255\ \mathrm{g\ $$mol^{-1}$$}$$

Question 11

A gas sample has a mass of 827 mg and occupies 0.200 L at 88°C and 1299 mbar. What is the molar mass of the gas? ($$R = 0.08314\ \mathrm{bar\ L\ $$mol^{-1}$$\ K$$^{-1}$$}$$; 1 bar = 1000 mbar)

Accepted Answer

$$M = 44.0\ \mathrm{g\ $$mol^{-1}$$}$$

Question 12

Which of the following best describes the effect of increasing temperature on the root mean square (rms) speed of gas molecules?

Accepted Answer

The rms speed increases as temperature increases.

Question 13

A helium-filled balloon has a volume of 6.0 L at 1.0 atm and 22°C. If it rises to an altitude where the pressure is 0.45 atm and the temperature is -21°C, what is the new volume of the balloon?

Accepted Answer

$$V_2$$ = \frac{$$P_1$$ $$V_1$$ $$T_2$$}{$$P_2$$ $$T_1$$} = \frac{(1.0)(6.0)(252)}{(0.45)(295)} = 11.4\ \mathrm{L}$$

Question 14

Which of the following is the correct expression for the density of a gas using the ideal gas law?

Accepted Answer

$$d = \frac{PM}{RT}$$

Question 15

Which of the following statements about diffusion and effusion is TRUE?

Accepted Answer

Effusion is the process by which gas molecules escape through a small hole into a vacuum.

Question 16

A steel container holds 2.00 mol of Ne at a certain pressure. If 1.00 mol of $$H_2 is $$added to the container at constant temperature and volume, what happens to the partial pressure of Ne?

Accepted Answer

It remains the same.

Question 17

Which of the following best explains why the pressure of a real gas is lower than predicted by the ideal gas law at low temperatures?

Accepted Answer

Intermolecular attractions cause gas molecules to collide with the container walls less forcefully.

Question 18

Which of the following is the correct form of the van der Waals equation for real gases?

Accepted Answer

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

General Chemistry I: Chapter 5 – Gases (Study Notes)

Guida di studio - Domande di pratica

Study guide - Flashcard