2 Robert BoyleIn the mid 1600's, Robert Boyle studied the relationship between the pressure P and the volume V of a confined gas held at a constant temperature. Boyle observed that the product of the pressure and volume are observed to be nearly constant. The product of pressure and volume is exactly a constant for an ideal gas. P * V = constant This relationship between pressure and volume is called Boyle's Law in his honor.
3 What Is Boyle’s Law?Boyle's Law states: If the temperature remains constant, the volume of a given mass of gas is inversely proportional to the absolute pressure.
4 Mathematically, Boyle's Law can be expressed as P1V1 = P2V2 V1 is the original volumeV2 is the new volumeP1 is original pressureP2 is the new pressure
5 EXAMPLEIf you have a 1 cubic foot balloon and double the pressure on it, it will be compressed to 1/2 cubic foot. Increase the pressure by 4, and the volume will drop to ¼ the size etc.
6 Sample ProblemThe volume of a sample of gas is 200 L at 740 mmHg. What would its volume be if the pressure on the sample were increased to 760 mmHg. Assume that the temperature remains constant. P1V1 = P2V2 P1: V1: P2: V2:
7 Boyle’s Law Practice Problems A gas occupies a volume of 458 mL at a pressure of 1.10 kPa and a temperature of 295 K. When the pressure is changed, the volume becomes 477 mL. If there has been no change in temperature, what is the new pressure? P1V1 = P2V2 P1: V1: P2: V2:
8 A gas occupies a volume of 2. 45 L at a pressure of 1 A gas occupies a volume of 2.45 L at a pressure of 1.03 atm and a temperature of 293 K. What volume will the gas occupy if the pressure changes to atm and the temperature remains unchanged. P1V1 = P2V2 P1: V1: P2: V2:
9 The cylinder of a car’s engine has a volume of 0 The cylinder of a car’s engine has a volume of L when the piston is at the bottom of the cylinder. When the piston is at the top of the cylinder the volume is L. If the cylinder is filled with air at an atmospheric pressure of mm Hg when the piston is at the bottom, what is the pressure in units of kPa when the piston is at the top of the cylinder? P1V1 = P2V2 P1: V1: P2: V2: