Q: Which equation correctly defines pressure as described in the study materials?

$$\text{pressure} = \frac{\text{force}}{\text{area}}$$

Q: Convert 0.311 atm to mm Hg.

$$0.311 \text{ atm} \times \frac{760 \text{ mm Hg}}{1 \text{ atm}} = 236 \text{ mm Hg}$$

Q: A sample of gas has a volume of 2.80 L at an unknown temperature. When the sample is submerged in ice water at $$0^\circC$$, its volume decreases to 2.57 L. What was its initial temperature in kelvin?

$$T_1$$ = \frac{(2.80 \text{ L})(273 \text{ K})}{2.57 \text{ L}} = 297 \text{ K}$$

Q: Which law describes the relationship between the volume and pressure of a gas at constant temperature?

Boyle's Law: $$P V = \text{constant}$$

Q: A mixture of gases contains 78% nitrogen, 21% oxygen, and 1% argon at a total pressure of 1 atm. What is the partial pressure of oxygen?

$$P_{O_2$} = 0.21 \text{ atm}$$

Question 1

Which statement best explains why drinking from a straw works?

Accepted Answer

Atmospheric pressure outside the straw pushes the liquid up when the pressure inside is lowered.

Question 2

What is the maximum theoretical height a column of water can be pushed up a straw by atmospheric pressure at sea level?

Accepted Answer

About 10.3 m

Question 3

According to the kinetic molecular theory, which of the following is NOT true about gas particles?

Accepted Answer

The average kinetic energy of gas particles is proportional to temperature in kelvin.

Question 4

Why are gases compressible while liquids are not?

Accepted Answer

There is much more empty space between gas particles than between liquid particles.

Question 5

Which equation correctly defines pressure as described in the study materials?

Accepted Answer

$$	ext{pressure} = \frac{	ext{force}}{	ext{area}}$$

Question 6

Convert 0.311 atm to mm Hg.

Accepted Answer

$$0.311 	ext{ atm} 	imes \frac{760 	ext{ mm Hg}}{1 	ext{ atm}} = 236 	ext{ mm Hg}$$

Question 7

A sample of gas has a volume of 2.80 L at an unknown temperature. When the sample is submerged in ice water at $$0^\circC$$, its volume decreases to 2.57 L. What was its initial temperature in kelvin?

Accepted Answer

$$T_1$$ = \frac{(2.80 	ext{ L})(273 	ext{ K})}{2.57 	ext{ L}} = 297 	ext{ K}$$

Question 8

Which law describes the relationship between the volume and pressure of a gas at constant temperature?

Accepted Answer

Boyle's Law: $$P V = 	ext{constant}$$

Question 9

A scuba diver at 20 m depth breathes air at 3 atm. If the diver ascends rapidly to the surface (1 atm) while holding his breath, what happens to the volume of air in his lungs?

Accepted Answer

The volume increases by a factor of 3.

Question 10

Which of the following is the correct form of the ideal gas law?

Accepted Answer

$$PV = nRT$$

Question 11

A mixture of gases contains 78% nitrogen, 21% oxygen, and 1% argon at a total pressure of 1 atm. What is the partial pressure of oxygen?

Accepted Answer

$$P_{O_2$} = 0.21 	ext{ atm}$$

Question 12

Which real-world scenario best illustrates Charles's Law?

Accepted Answer

A hot air balloon rises as the air inside is heated and expands.

Question 13

If a 4.8 L sample of helium contains 0.22 mol, how many additional moles are needed to reach a volume of 6.4 L at constant temperature and pressure?

Accepted Answer

0.07 mol

Question 14

Which of the following is a major air pollutant that can displace oxygen in the blood, causing the heart and lungs to work harder?

Accepted Answer

Carbon monoxide (CO)

Question 15

A sample of gas has a mass of 0.136 g, a volume of 0.112 L, a temperature of 298 K, and a pressure of 1.06 atm. What is its molar mass?

Accepted Answer

$$	ext{Molar mass} = \frac{0.136 	ext{ g}}{4.85 	imes 10$$^{-3}$$ 	ext{ mol}} = 28.0 	ext{ g/mol}$$

Question 16

Which law would you use to calculate the final pressure of a gas sample when both its volume and temperature change?

Accepted Answer

Combined Gas Law: $$\frac{P_1$ V_1$}{T_1$} = \frac{P_2$ V_2$}{T_2$}$$

Question 17

At STP, what volume does 1 mole of any ideal gas occupy?

Accepted Answer

22.4 L

Question 18

Which of the following best describes Dalton's Law of Partial Pressures?

Accepted Answer

The total pressure of a mixture of gases is the sum of the partial pressures of its components.

Study Notes: Gases and Gas Laws (Chapter 11, Introductory Chemistry)

Guida di studio - Domande di pratica

Study guide - Flashcard