Question 1

Which of the following best describes the difference between a gas and a vapor?

Accepted Answer

A vapor is the gaseous form of a substance that is normally a liquid or solid at room temperature, while a gas is normally in the gaseous state at ordinary temperatures and pressures.

Question 2

Which of the following is NOT a characteristic property of gases?

Accepted Answer

High density (g/L)

Question 3

A barometer is used to measure atmospheric pressure. If the atmospheric pressure increases, what happens to the height of the mercury column in the barometer?

Accepted Answer

The height of the mercury column increases.

Question 4

Standard atmospheric pressure is defined as the pressure that supports a column of mercury exactly 760 mm high at 0°C at sea level. What is this pressure in atmospheres (atm)?

Accepted Answer

$$1.00\ 	ext{atm}$$

Question 5

Which of the following correctly expresses the relationship described by Boyle's Law?

Accepted Answer

$$P_1V_1 = P_2V_2$$

Question 6

At STP, one mole of any ideal gas occupies what volume?

Accepted Answer

$$22.414\ 	ext{L}$$

Question 7

A 10.0 L sample of carbon monoxide gas is collected at STP. What is the mass of CO in the sample? (Molar mass of CO = 28.01 g/mol)

Accepted Answer

$$12.5\ 	ext{g}$$

Question 8

Which equation represents the combined gas law for a fixed amount of gas?

Accepted Answer

$$\dfrac{P_1V_1}{T_1$} = \dfrac{P_2V_2}{T_2$}$$

Question 9

The ideal gas law is given by which of the following equations?

Accepted Answer

$$PV = nRT$$

Question 10

A 2.0 L flask contains O$$_2$$ gas at a pressure of 2.3 atm and a temperature of 26°C. How many moles of O$$_2$$ are in the flask? ($$R = 0.0821\ 	ext{L} \cdot 	ext{atm} / 	ext{mol} \cdot 	ext{K})$$

Accepted Answer

$$0.19\ 	ext{mol}$$

Question 11

If the flask from the previous question is cooled to $$-40\ ^\circ	ext{C}$$, what is the new pressure of the O$$_2$$ gas (assuming constant volume and moles)?

Accepted Answer

$$1.3\ 	ext{atm}$$

Question 12

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

Accepted Answer

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

Question 13

A sample of CO$$_2 is at 745 mm Hg $$and 65°C. What is the density of CO$$_2$$ under these conditions? (Molar mass of CO$$_2 = 44.01 g/$$mol, $$R = 0.0821\ 	ext{L} \cdot 	ext{atm} / 	ext{mol} \cdot 	ext{K})$$

Accepted Answer

$$1.02\ 	ext{g/L}$$

Question 14

Which of the following is NOT an assumption of the ideal gas law?

Accepted Answer

Gas molecules are attracted to each other strongly.

Question 15

A meteorologist reports the barometric pressure as 29.12 inches of mercury. What is this pressure in mm Hg? (1 inch = 25.4 mm)

Accepted Answer

$$739\ 	ext{mm Hg}$$

Question 16

Which of the following best explains why gases are highly compressible?

Accepted Answer

Gas molecules are separated by large distances relative to their size.

Question 17

A reaction is carried out: $$3	ext{NO}_2(g) + 	ext{H}_2	ext{O}(l) ightarrow 2	ext{HNO}_3(aq) + 	ext{NO}(g). If 450 L of NO$_2$$ gas at 5.0 atm and 295 K is used, how many moles of HNO$$_3$$ can be produced? ($$R = 0.0821\ 	ext{L} \cdot 	ext{atm} / 	ext{mol} \cdot 	ext{K})$$

Accepted Answer

$$186\ 	ext{mol}$$

Question 18

Which of the following is the SI unit for pressure?

Accepted Answer

Pascal (Pa)

Question 19

Which property of gases allows them to mix completely with other gases in any proportion?

Accepted Answer

Infinitely miscible

Question 20

If the density of a gas is measured in g/L, which of the following is a correct rearrangement of the ideal gas law to solve for molar mass $$M$$?

Accepted Answer

$$M = \dfrac{dRT}{P}$$

Lecture 20

Study Guide - Practice Questions

Study Guide - Flashcards