Boyle’s Law Pressure and Volume of a gas are inversely related at a constant temperature and constant number of particles.

Using Boyle’s Law A balloon has a volume of 1.5 L at 20 o C and 101 kPa. If the balloon is placed into a vacuum jar and the pressure is lowered to 50 kPa, what is the new volume of the balloon?

Boyle’s Law Lab

Organize the givens Temperature constant Number moles constant Press 1 = 101 kPa Press 2 = 50 kPa Vol 1 = 1.5 L Vol 2 = ? mL Find the equation P1 x V1 = P2 X V2 Isolate the variable V2 = P1 X V1 P2

Plug and Chug V2 = P1 X V1 P2 V2 = 101kPa x 1.5 L= 3.0 L 50kPa

Charles’s Law Demonstration

Problem from Demonstration Professor Bob fills the glove to 0.75 liters of air at 20 o C and 1 atm of pressure. Liquid nitrogen at 1 atm liquid nitrogen has a boiling temperature of -198 o C. What is the volume of the balloon in the container with liquid nitrogen?

Who’ Gas Law? Organize the givens Pressure constant Number moles constant Temp 1 = 20 o C + 273= 293K Temp 2 = -198 o C + 273= 75K Vol 1 = 0.75L Vol 2 = ? L Find the equation V1 = V2 T1 T2 Isolate the variable

Plug and Chug V2 = V1 x T2 T1 V2 = 0.75L x 75K= 0.19L 298 Why can’t we use o C to solve this problem?

Gay-Lussac’s Law P T Courtesy Christy Johannesson Temperature (K) Pressure (kPa) P/T (kPa/K)

Gay-Lussac’s Law The pressure and absolute temperature (K) of a gas are directly related *at constant mass & volume P T Courtesy Christy Johannesson