### Application of Charle's law and Boyle's law

Boyle's Law

Boyle's Law states the volume of a definite quantity of dry gas is inversely proportional to the pressure, provided the temperature remains constant.

Mathematically Boyle's law can be expressed as P1V1 = P2V2

• V1 is the original volume
• V2 is the new volume
• P1 is original pressure
• P2 is the new pressure

Suppose you have a gas with 45.0 ml of volume and has a pressure of 760.mm. If the pressure is increased to 800mm and the temperature remains constant then according to Boyle's Law the new volume is 42.8 ml.

(760mm)(45.0ml) = (800mm)(V2)
V
2=42.8ml

Charle's Law

Charle's Law can be stated as the volume occupied by any sample of gas at a constant pressure is directly proportional to the absolute temperature.

V / T =constant

• V is the volume
• T is the absolute temperature (measured in Kelvin)

Charles's Law can be rearranged into two other useful equations.

V1 / T1 = V2 / T2

• V1 is the initial volume
• T1 is the initial temperature
• V2 is the final volume
• T2 is the final temperature

V2 = V1 (T2 / T1)

• V2 is the final volume
• T2 is the final temperature
• V1 is the initial volume
• T1 is the initial temperature

Important: Charles's Law only works when the pressure is constant.

Note: Charles's Law is fairly accurate but gases tend to deviate from it at very high and low pressures.