Educational worksheet on the behavior of gases, covering compressibility and factors affecting gas pressure.

Let's go through the worksheet "The Behavior of Gases" (Section 14.1) and solve each question with explanations.

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1. Look at Figure 14.1 on page 413. How does an automobile air bag protect the crash dummy from being broken as a result of impact?

Answer:
*The gases used to inflate the airbag are able to absorb a considerable amount of energy when they are compressed.*

Explanation:
When a car crashes, the airbag rapidly inflates with gas (usually nitrogen). As the dummy hits the airbag, the gas inside gets compressed. Because gases are compressible, they can absorb the kinetic energy of the impact, slowing down the dummy gently instead of allowing it to stop abruptly. This reduces the force exerted on the dummy, preventing injury.

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2. What theory explains the behavior of gases?

Answer:
Kinetic theory

Explanation:
The kinetic molecular theory (KMT) explains how gases behave. It states that:
- Gas particles are in constant, random motion.
- They have negligible volume compared to the space between them.
- They exert pressure by colliding with container walls.
- Collisions are elastic (no net loss of energy).
- The average kinetic energy is proportional to temperature.

This theory helps explain properties like pressure, diffusion, and compressibility.

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3. Circle the letter next to each sentence that is true concerning the compressibility of gases.

Correct Answers:
✔ a. The large relative distances between particles in a gas means that there is considerable empty space between the particles.
✔ b. The assumption that particles in a gas are relatively far apart explains gas compressibility.
✘ c. Compressibility is a measure of how much the volume of matter decreases under pressure. *(This is actually correct — but note: this definition is accurate, so it should be circled too.)*
✔ d. Energy is released by a gas when it is compressed.

Wait — let’s evaluate carefully:

- a. TRUE – There's lots of empty space, which allows compression.
- b. TRUE – That’s why gases are compressible.
- c. TRUE – Yes, compressibility measures how much volume decreases under pressure. (This is a valid definition.)
- d. TRUE – When gas is compressed, work is done on it, and energy is stored (but technically, energy is *not* "released"; it's stored or transferred). Wait — this one is tricky.

Actually, d says: *"Energy is released by a gas when it is compressed."*
This is FALSE. Compression requires energy input — the gas gains internal energy. So energy is not released, it’s absorbed.

So only a, b, and c are correct.

But c is a bit ambiguous. Let’s clarify:

> Compressibility is often defined as the fractional change in volume per unit increase in pressure. So yes, it does measure how much volume decreases under pressure.

Therefore, a, b, and c are true.

But d is false.

✔ Correct answers: a, b, c

Note: Some textbooks may define compressibility differently, but generally:
- a, b, c are correct.
- d is incorrect — energy is *absorbed*, not released, during compression.

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4. List the name, the symbol, and a common unit for the four variables that are generally used to describe the characteristics of a gas.

| Letter | Name | Symbol | Common Unit |
|--------|------------------|--------------|--------------------|
| a. | Pressure | P | kilopascals (kPa) |
| b. | Volume | V | liters (L) |
| c. | Temperature | T | kelvins (K) |
| d. | Amount of gas | n | moles (mol) |

Explanation:
These four variables (P, V, T, n) are used in the ideal gas law:
$$ PV = nRT $$

- Pressure (P): Force per unit area; units include kPa, atm, mmHg.
- Volume (V): Space occupied; usually in liters.
- Temperature (T): Must be in Kelvin for gas laws.
- Amount of gas (n): Measured in moles.

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5. What keeps the raft in Figure 14.3 inflated?

Answer:
*The air pressure exerted by the enclosed gas keeps the raft inflated.*

Explanation:
The raft is filled with air (gas). The gas molecules are in constant motion and collide with the inner walls of the raft. These collisions create pressure. As long as the pressure inside the raft is greater than the outside atmospheric pressure, the raft stays inflated. If air leaks out, pressure drops, and the raft deflates.

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✔ Final Summary of Answers:

1. The gases used to inflate the airbag are able to absorb a considerable amount of energy when they are compressed.
2. Kinetic theory
3. a, b, c (correct sentences about compressibility)
4.
a. Pressure, P, kilopascals
b. Volume, V, liters
c. Temperature, T, kelvins
d. Amount of gas, n, moles
5. The air pressure exerted by the enclosed gas keeps the raft inflated.

All answers match the provided responses in the image. Great job!