Rank in order, from highest to lowest, the temperatures $T_1=0\text{K,}{T}_2=0\text{°}\text{C,}$ and $T_3=0\text{°}\text{F}$.

The sample in an experiment is initially at $10\text{°}\text{C}$. If the sample’s temperature is doubled, what is the new temperature in $\text{°}\text{C}?$

1. Is there a highest temperature at which ice can exist? If so, what is it? If not, why not?

2. Is there a lowest temperature at which water vapor can exist? If so, what is it? If not, why not?

The cylinder in FIGURE Q18.4 is divided into two compartments by a frictionless piston that can slide back and forth. If the piston is in equilibrium, is the pressure on the left side greater than, less than, or equal to the pressure on the right? Explain.

FIGURE Q18.4

A gas is in a sealed container. By what factor does the gas temperature change if:

1. The volume is doubled and the pressure is tripled?

2. The volume is halved and the pressure is tripled?

A gas is in a sealed container. The gas pressure is tripled and the temperature is doubled.

1. Does the number of moles of gas in the container increase, decrease, or stay the same?

2. By what factor does the number density of the gas increase?

An aquanaut lives in an underwater apartment 100 m beneath the surface of the ocean. Compare the freezing and boiling points of water in the aquanaut’s apartment to their values at the surface. Are they higher, lower, or the same? Explain.

1. A sample of water vapor in an enclosed cylinder has an initial pressure of 500 Pa at an initial temperature of $-0.01\text{°}\text{C}$. A piston squeezes the sample smaller and smaller, without limit. Describe what happens to the water as the squeezing progresses.

2. Repeat part a if the initial temperature is $0.03\text{°}\text{C}$ warmer.

A gas is in a sealed container. By what factor does the gas pressure change if:

1. The volume is doubled and the temperature is tripled?

2. The volume is halved and the temperature is tripled?

A gas undergoes the process shown in FIGURE Q18.10. By what factor does the temperature change?

FIGURE Q18.10

The temperature increases from 300 K to 1200 K as a gas undergoes the process shown in FIGURE Q18.11. What is the final pressure?

FIGURE Q18.11

A student is asked to sketch a $pV$ diagram for a gas that goes through a cycle consisting of (a) an isobaric expansion, (b) a constant-volume reduction in temperature, and (c) an isothermal process that returns the gas to its initial state. The student draws the diagram shown in FIGURE Q18.12. What, if anything, is wrong with the student’s diagram?

FIGURE Q18.12