Chapter 16: Solids, Liquids, and Gases Section 3: Behavior of Gases Hot air balloons use buoyancy and thermal expansion to rise through the air. As the air inside the balloon is heated, what happens to the volume of the balloon? As the temperature increases inside the balloon, what happens to the pressure? How might a balloon descend (come down)? http://www.pkwy.k12.mo.us/west/teachers/anderson/pack7/kmt/balloon.jpg

Behavior of Gases Pressure is measured in units called pascals (Pa) Collisions of particles in air result in atmospheric pressure. Moving particles colliding with the inside walls of a container result in gas pressure.

Boyle’s Law Relates pressure and volume An increase in pressure causes a decrease in volume. A decrease in pressure causes an increase in volume. Pressure multiplied by volume is always equal to a constant, as long as temperature is constant. P1 X V1 = P2 X V2

Boyle’s Law

Boyle’s Law Animation http://www.youtube.com/watch?v=Wue_9SUFLi0

Charles’s Law Relates volume and temperature An increase in temperature causes an increase in volume. A decrease in temperature causes a decrease in volume. Volume divided by temperature is always equal to a constant, as long as pressure is constant. V1 = V2 T1 T2

Charles’s Law Animation http://www.youtube.com/watch?v=ZvrJgGhnmJo

Gay-Lussac’s Law Relates temperature and pressure An increase in temperature causes an increase in pressure. A decrease in temperature causes a decrease in pressure. Pressure divided by temperature is always equal to a constant, as long as volume is constant. P1 = P2 T1 T2

Gay-Lussac’s Law Animation http://www.youtube.com/watch?v=GnJ_VbWP9WM

Which gas laws are demonstrated in the following: Boyle’s Law? Charles’s Law? or Gay-Lussac’s Law? http://www.youtube.com/watch?v=ejEJGNLTo84 http://www.youtube.com/watch?v=2WJVHtF8GwI&feature=related