Gases Copyright Houghton Mifflin Company All rights reserved

Gases Copyright © Houghton Mifflin Company. All rights reserved.

A skydiver leaps into the earth's atmosphere, which is composed of a mixture of gases. Source: Brian Erler/Taxi/Getty Images Copyright © Houghton Mifflin Company. All rights reserved. 2

Steve Fossett flies his balloon Solo Spirit, over the east coast of Australia during his attempt to make the first solo balloon flight around the world. Source: AP Photo/Steve Holland

Figure 12. 1: The pressure exerted by the gases in the atmosphere can be demonstrated by boiling water in a can. Copyright © Houghton Mifflin Company. All rights reserved. 4

Figure 12. 2: When a glass tube is filled with mercury and inverted in a dish of mercury at sea level, the mercury flows out of the tube until a column approximately 760 mm high remains.

Figure 12. 3: A device (called a manometer) for measuring the pressure of a gas in a container. Copyright © Houghton Mifflin Company. All rights reserved. 6

Checking the air pressure in a tire.

Copyright © Houghton Mifflin Company. All rights reserved. 8

Figure 12. 4: A J-tube similar to the one used by Boyle.

Figure 12. 5: A plot of P versus V from Boyle’s data in Table 12. 1.

Figure 12. 6: Illustration of Boyle’s law. Copyright © Houghton Mifflin Company. All rights reserved. 11

Neon signs in Hong Kong Source: Dave Jacobs/Stone/Getty Images Copyright © Houghton Mifflin Company. All rights reserved. 12

Figure 12. 7: Plots of V (L) versus T (°C) for several gases.

Figure 12. 8: Plots of V versus T as in Figure 12. 7, except that here the Kelvin scale is used for temperature.

The air in a balloon expands when it is heated. This means that some of the air escapes from the balloon, lowering the air density inside and thus making the balloon buoyant. Source: John A. Rizzo/ Photo. Disc/Getty Images

Researchers take samples from a steaming volcanic vent at Mount Baker in Washington. Source: USGA Photo by T. Casadevall Copyright © Houghton Mifflin Company. All rights reserved. 16

Figure 12. 9: The relationship between volume V and number of moles n. As the number of moles is increased from 1 to 2 (a to b), the volume doubles. Copyright © Houghton Mifflin Company. All rights reserved. 17

Popcorn popping.

Figure 12. 10: When two gases are present, the total pressure is the sum of the partial pressures of the gases. Copyright © Houghton Mifflin Company. All rights reserved. 19

Figure 12. 11: The total pressure of a mixture of gases depends on the number of moles of gas particles (atoms or molecules) present, not on the identities of the particles. Copyright © Houghton Mifflin Company. All rights reserved. 20

Divers use a mixture of oxygen and helium in their breathing tanks when diving to depths greater than 150 feet. Source: Kurt Amsler/Vandystadt/Allsport/Getty Images Copyright © Houghton Mifflin Company. All rights reserved. 21

Figure 12. 12: The production of oxygen by thermal decomposition of KCl. O 3. Copyright © Houghton Mifflin Company. All rights reserved. 22

Copyright © Houghton Mifflin Company. All rights reserved. 23

Copyright © Houghton Mifflin Company. All rights reserved. 24

Figure 12. 13: (a) A gas confined in a cylinder with a movable piston. (b) The temperature of the gas is increased at constant pressure Pext. Copyright © Houghton Mifflin Company. All rights reserved. 25