In order to compare two gases, we choose a standard temperature and pressure: STP: standard temperature and pressure → K and 101 kPa → one mole of gas has a volume of 22.4 L SATP: standard ambient temperature and pressure → K and 100 kPa → one mole of gas has a volume of 24.8 L

gases exert a pressure on the walls of their container. P F (N) A (m 2 )  SI unit: 1 N/m 2 = 1 Pascal (Pa) pressure is defined as force per unit area:

The atmospheric pressure can be measured using a barometer.

760 mm Hg = 1 atm= 101 kPa Standard atmospheric pressure supports a column of mercury about 760 mm high.

If the barometer reads mm Hg, what is the atmospheric pressure in atm and kPa? = atm mm Hg 760 mm Hg 1 atm = kPa kPa mm Hg 760 mm Hg

Pressure Conversions: atm to mmHg mmHg to atm atm to kPa kPa to atm mmHg to kPa kPa to mmHg Temperature Conversions: Kelvin to Celsius Kelvin to Celsius Celsius to Kelvin Celsius to Kelvin Celsius to Kelvin 665 mm Hg atm 96.8 kPa atm kPa mm Hg

► Practice, p.150 #1 - 4

Graph the following information Pressure (KPa) Volume (L) K (VP) P 1 V 1 = K = P 2 V 2 Is there a relationship between pressure and volume? volume pressure

For a given mass of gas at constant temperature, the volume of a gas varies inversely with pressure. P 1 V 1 = P 2 V 2

► Practice, p.152 #5 - 10

Graph the following data Temperature (K)Volume (L) K (V/T) V 1 /T 1 = K = V 2 /T 2 temperature volume Is there a relationship between pressure and volume?

V versus T for different gases

Charles discovered that volume is directly proportional to its Kelvin temperature if a fixed mass remains under constant pressure. V 1 V 2 T 1 T 2 =

► Practice, p.154 # ► Practice, p.156 #

V 1 P 1 = V 2 P 2 T 1 T 2

► Practice, p.159 #20 – 23,25-26 ► Section 4.1 Questions #1 – 7, 9a,