Gas Laws

Units Used With Gas Laws

• PRESSURE: The force applied by many gas particles colliding with each other.

1. Atmospheres (atm) STP= 1atm2. Pounds per square inch (PSI) STP= 14.73. Pascal (Pa) SI UNIT! STP= 101.3

kPa4. Millimeters of Mercury (mm Hg) STP= 7605. Torr (named after Torricelli) STP= 760

– Evangelista Torricelli invented the barometer which used mercury.

Units Used With Gas Laws 2

• Temperature:1. Celsius (°C) STP=02. Kelvin (K) STP=273• To convert °C to K:

K=°C + 273• Example: 23°C =?K

23°C + 273= 296K

Units Used With Gas Laws 3

• Volume:

• Volume can be measured in liters (L) or milliliters (mL).

3 Major Gas Laws• Boyle’s Law

• Charles’s Law

• Gay Lussac’s Law

Boyle’s Law• Robert Boyle

(1627-1691) • Born in Ireland,

and died in England.

• 1st person to do an actual study on how volume and pressure effect each other.

Boyle’s Law• In all of Boyle’s

studies, the temperature of the gas is always constant.

• Boyle came up with equation:

P1*V1=P2*V2

• Boyle’s equation indicates an inverse relationship between pressure and volume.

• If the pressure goes up, than the volume must go down.

volume, pressure

Boyle’s Law (P vs. V)

Charles’s Law• Jacques Charles

(1746-1823)• He built the first

large balloon.• He studied the

effects that temperature had on the volume of a gas.

Charles’s Law 2

• In all of Charles’s studies, the pressure is always constant, and the temp. in always in Kelvin.

• Charles came up with the equation:V1/T1 = V2/T2

• Charles’s equation indicates that there is a direct relationship between the temperature of a gas and it’s volume.

volume, temp. temp., volume

Charles’s Law (T vs. V)

Gay-Lussac’s Law

• Joseph Gay-Lussac (1778-1850)

• A French chemist who traveled over 7,000 meters in altitude in a hot air balloon.

• He studied the effects that temperature had on the pressure of gases.

Gay-Lussac’s Law 2

• Lussac’s greatest discovery was the relationship between pressure and temperature.

• The volume for his problems will always be constant, and the temp. must be in Kelvin.

• Lussac’s equation:P1/T1 = P2/T2

• This equation indicates that there is a direct relationship between pressure and temperature.

temp., pressure pressure, temp.

The Ideal Gas Law• This gas law is used to determine the

amount of gas, in moles, in a system.• The equation is:

PV=nRTn=the number of moles of a gas

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