Boyle’s Law Mathematical relationship between pressure and volume.

Pressure and Volume – Inverse Relationship For a given sample of gas, as the volume increases, the pressure __________________. The opposite is true, as the volume decreases, the pressure ___________________.

Look at your data from Monday For 10 data points, calculate the value of the pressure x the volume. For a given sample of gas, at a constant temperature… P x V = k (a constant)

BOYLE’S Law If temperature is held constant, the product of the initial pressure x volume = the product of a final pressure x volume since each equal the constant. P 1 V 1 = k P 2 V 2 = k P 1 V 1 = k = P 2 V 2 P 1 V 1 = P 2 V 2

Example 1 – applying Boyle’s Law A diver blows a 0.75 L air bubble 10 m under water. As the bubble rises to the surface, the pressure decreases from 2.25 atm to 1.03 atm. Calculate the volume of the bubble at the surface. Formula: P 1 V 1 = P 2 V 2 V 2 = P 1 V 1 /P 2 V 2 = (2.25 atm)x(0.75 L)/(1.03 atm) V 2 = 1.6 L

Example 2 – applying Boyle’s Law Under a pressure of atm, helium fills a balloon to 1.00 L. What would the pressure be if the volume of the balloon stretched to 2.00 L? Formula: P 1 V 1 = P 2 V 2 P 2 = P 1 V 1 /V 2 P 2 = (0.988 atm)x(1.00 L)/(2.00 L) P 2 = atm

STP Standard Temperature and Pressure Temperature: 0 °C (32 °F or 273 Kelvin) Pressure: 1 atm ( kPa, 14.7 PSI, 760 mmHg, or 760 Torr).kPaPSI