Ch. 10: Physical Properties of Gases 10.3 Gas Laws: Relationships between volume, temperature, pressure, and amount of gas.

Boyle’s Law: P and V as one increases, the other decreases inversely proportional pressure is caused by moving molecules hitting container walls

Boyle’s Law: P and V Boyle’s Law: the V of fixed mass of gas varies inversely with P at a constant T. What kind of graph is V vs. P?

Boyle’s Law

Example: Boyle’s Law Consider a 1.53-L sample of gaseous SO2 at a pressure of 5.6 x 103 Pa. If the pressure is changed to 1.5 x 104 Pa at constant temperature, what will be the new volume of the gas?

Charles’ Law: V and T if P is constant, gases expand when heated when T increases, gas molecules move faster and collide with the walls more often and with greater force to keep the P constant, the V must increase

Charles’ Law: V and T Problem: if we use Celsius, we could end up with negative values from calculations in gas laws for volumes we need a T system with no negative values: Kelvin Temperature Scale starts at -273.15 ° C = absolute zero = 0 K lowest possible temperature

Charles’ Law: V and T Charles’ Law: the V of fixed mass of gas at constant P varies directly with Kelvin T. What kind of graph is V vs. T?

Charles’ Law discovered by French physicist, Jacques Charles in 1787 first person to fill balloon with hydrogen gas and make solo balloon flight

Example: Charles’ Law A sample of gas at 15°C and 1 atm has a volume of 2.58 L. What volume will this gas occupy at 38°C and 1 atm?