Factors

Temperature, Volume, and Pressure

Measuring Gases

Gases can change volume.  The volume is affected by temperature an pressure

Volume

The space matter fills, cm³, ml, L, m³. A gases volume is the volume of its container

Temperature

Atoms and molecules are in constant motion.  Temperature is the average energy of motion of the particles of matter

Pressure

Gas particles collide with the walls of their container.  Pressure is equal to the force of each particle hitting the area of the container.  P = force/area

Force is measured in newtons (N). Area is measured in m².  Pressure is N/m² or pascals (Pa).

You can raise pressure by putting more gas into the container (basketball).  More particles hit the container.

Temperature and Volume

Charles’ Law

See fig 16 p106 Balloon cools and shrinks

Jacques Charles noticed a relationship between temperature and volume.  When the temperature of a gas is decreased at a constant pressure, its volume decreases.

Graphing Charles’ Law

As Temperature increases, Volume increases.  The graph of this is a straight line increasing from the origin.  Directly Proportional

Pressure and Volume

Think bike pump. 

Boyle’s Law:  When volume of gas is increased, pressure decreases.  When volume of gas is decreased, pressure increases. 

Graphing Boyle’s Law

As Volume increases, Pressure decreases.  This relationship is inversely proportional.

Pressure and Temperature

Increasing Temperature

The faster matter moves, the harder it hits the container (force is mass x acceleration).

This raises pressure.  Decreasing temperature decreases pressure