Chapter 18: A Macroscopic Description of Matter

A gas at $100°C$fills volume $V_0$. If the pressure is held constant, what is the volume if

(a) the Celsius temperature is doubled and

(b) the Kelvin temperature is doubled?

The total lung capacity of a typical adult is $5.0L$. Approximately $20\%$of the air is oxygen. At sea level and at a body temperature of $37°C$, how many oxygen molecules do the lungs contain at the end of a strong inhalation?

A $20-cm$-diameter cylinder that is $40cm$long contains $50g$of oxygen gas at$20°C$

a. How many moles of oxygen are in the cylinder?

b. How many oxygen molecules are in the cylinder?

c. What is the number density of the oxygen?

d. What is the reading of a pressure gauge attached to the tank

The solar corona is a very hot atmosphere surrounding the visible surface of the sun. X-ray emissions from the corona show that its temperature is about $2\times {10}^{6}K$. The gas pressure in the corona is about $0.03Pa$. Estimate the number density of particles in the solar corona.

A gas at temperature $T_0$and atmospheric pressure fills a cylinder. The gas is transferred to a new cylinder with three times the volume, after which the pressure is half the original pressure. What is the new temperature of the gas?

a. Is there a highest temperature at which ice can exist? If so,

what is it? If not, why not?

b. Is there a lowest temperature at which water vapor can exist?

If so, what is it? If not, why not?

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

b. Is there a lowest temperature at which water vapour can exist?

if so, what is it? If not, why not?

$0.020mol$ of gas undergoes the process shown in FIGURE EX18.37.

a. What type of process is this?

b. What is the final temperature in $°C$?

c. What is the final volume $V_2$?

$0.0050mol$ of gas undergoes the process $1\to 2\to 3$ shown in Figure P16.38. What are

(a) temperature $T_1$,

(b) pressure $p_2$, and

(c) volume $V_3$?

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