Chapter 16, Section 3 Behavior of Gases Created by Izabella Mingolla, Aden Rusch, Drew Turk, Jackie Robinson, Kaitlyn Ayral, Melissa Besanceney, and Taly Sterle

Introduction Often, gases are confined in containers. When gas is confined within a container, the air particles will collide against the walls. These collisions push the walls outward. If more air is pumped into the balloon, the amount of air particles will increase, collisions occur more often, and so the balloon expands. For a tire, it works a bit differently because it is not as elastic as a balloon. So, because it can not expand very much, its pressure increases.

Pressure Often, gases are confined in containers that can be any shape or size. Pressure is measured in pascals. Pascal= 1N/m2 Most pressures so small are referred to in kilopascals or kPa.

Boyle’s Law If you decrease the volume of a container full of gas, then the pressure increases. The opposite is also true. If you increase the volume of the container of gas, then the pressure will decrease.

Boyle’s Law in Action Decreasing the size of the container in which the gas is held will, in turn, increase the amount of pressure in the container. Take for instance, a balloon. Decreasing the size of the balloon creates more pressure, thus forcing more air out. Volume/Pressure Equation: P1V1 = P2V2

Pressure-Temperature Relationship If you heat an enclosed gas, the particles of the gas will strike the walls of the canister more often. If the canister is rigid, its volume cannot increase. Therefore, its pressure increases. If the pressure becomes greater than the canister can hold, it will explode! At a constant volume, an increase in temperature results in an increase in pressure.

Charles’s Law The volume of a gas increases with the increase of temperature, as long as there is no change in pressure. The opposite is also true. If the temperature decreases, so will the volume.

The Kinetic Theory of Matter When a gas is heated, the speed of the particles increases and the temperature increases. Because the particles move faster, they strike the walls of their container with more force and more often. If the container has no room to expand, the pressure goes up. If it can expand, then the volume will increase.

Using Charles’s Law If a balloon was outside with the sun bearing heat down on the balloon, the balloon would increase in volume. If you also exposed a balloon to extreme cold, like putting it in your freezer, the balloon would decrease in volume.

The end! :) Thanks for watching!