1.  Boyle’s Law:At a constant temperature, the volume of a sample of gas varies inversely with the pressure exerted on it. Mathematically: P 1 V 1 = P 2 V 2  Informally:If P goes up, then V goes down OR if P goes down, then V goes up.

2. Sample Problems: 1) A sample of gas has a volume of 1.80 L at a pressure of 300. mm. What will be its new volume if the pressure on the gas is increased to 500. mm?

3. 2)A gas has a volume of 525 mL at 700 mm pressure. What pressure is needed to reduce the volume to 140 mL?

4. 3) A 2.00 L container is filled with gas at a pressure of 480. kPa. What volume would the gas occupy if it were released so as to be at standard pressure?

5.  Temperature increases, volume increases. Temperature decreases, volume decreases.  A graph of temperature vs. volume shows a direct relationship, which is a straight-line graph. This is converted to an exact simple direct relationship when volume is plotted against Kelvin temperature.

6. Charles’ Law:The volume of a gas varies directly with the Kelvin temperature. Mathematically: This is the same type of relationship as for pressure and temperature and can be expressed in a similar fashion: V 1 =V 2 T 1 T 2  Volume – any units as long as the same on both sides  Temperature – only in Kelvin

7. Sample Problem 1: A sample of gas occupies a volume of 50.0 L at 25 o C. What will the volume be at standard temperature (0 o C)?

8. Sample Problem 2: A gas sample has a volume of 180 mL when the temperature is 43 o C. To what temperature must the gas be cooled to reduce the volume to 150 mL?