 The average kinetic energy (energy of motion ) is directly proportional to absolute temperature (Kelvin temperature) of a gas  Example  Average energy determines the temperature of the sample ;  If absolute temperature doubles, the average kinetic energy doubles Kinetic energy increases, particles move faster, number of collisions increase (explains why gases expand when heated)

Shows the relationship among pressure, temperature, and the 3 phases of water (gas, liquid & solid). Triple Point – conditions at which all 3 phases can exist in equilibrium together

 Heat Energy transferred due to differences in temperature  Temperature Measure of the average kinetic energy of particles composing a material  Pressure Force per unit area  Volume The amount of space a material occupies

 Pressure and volume are indirectly related  Pressure and 1/volume are directly related

1. A balloon initially occupies 12.4 L at 1.00 atm. What will be the volume at atm? 2. A sample of gas expands from 10.0 L to 30.0 L. If the initial pressure was 1140 mm Hg, what is the new pressure?

 Using Boyles law Calculate: A balloon contains 40.0 L of a gas at kPa. What is the volume of the gas when the balloon is brought to an altitude where the pressure is only 10.0 kPa? (Assume that the temperature remains constant.)

 Temperature and volume are directly related  At constant pressure  Absolute zero Theoretically, point at which all motion stops. The temperature at which volume of a gas becomes zero when the plot of temperature vs. volume is extrapolated.

1. Calculate the decrease in temperature when 2.00 L at 20.0°C is compressed to 1.00 L. 2. A gas occupies mL at a temperature of 27.0°C. What is the volume at 132.0°C?

 Temp and pressure are directly related  Absolute zero The temperature at which the pressure of a gas becomes zero when a plot of pressure versus temperature for a gas is extrapolated  -273  C = 0 K or K =  C + 273

1. Consider a container with a volume of 22.4 L filled with a gas at 1.00 atm at 273 K. What will be the new pressure if the temperature increases to 298K?

2. A container is initially at 47 mm Hg and 77K (liquid nitrogen temperature.) What will the pressure be when the container warms up to room temperature of 25  C?

3. A thermometer reads a pressure of 248 Torr at 0.0  C. What is the temperature when the thermometer reads a pressure of 345 Torr?

 STP (standard temperature and pressure)  T = 273K (which is 0°C)  P = 1 atm, kPa, 760 mmHg, 760 torr  V = 22.4 L (one mole of gas)  Formula P 1 V 1 =P 2 V 2 T 1 T 2

 10.0 cm 3 volume of a gas measured 75.6 kPa and 60.0  C is to be corrected to correspond to the volume it would occupy at STP.

 PV = nRT P = pressure V = volume n = number of moles (“mol”) R = “universal gas constant” T = temperature in K  Calculate R if pressure is in atm:

 Calculate R if pressure is in kPa:  Calculate R if pressure is in torr or mm Hg:

 Calculate the temperature of moles of a gas occupying a volume of 20.0 L with a pressure of 99.9 kPa.  Calculate the moles of a gas occupying a volume of mL with a temperature of 25.5  C and a pressure of 755 torr.

 The total pressure in a container is the sum of the partial pressures of all the gases in the container  P total = P 1 + P 2 + P 3  P total = 100 KPa KPa KPa = 550 KPa

 Air contains oxygen, carbon dioxide, and trace amounts of other gases. What is the partial pressure of oxygen at KPa of total pressure if the partial pressure of nitrogen, carbon dioxide, and other gases are 79.1 KPa, 0.04 KPa, and 0.94 KPa respectively?  P total = P O 2 + P N 2 + P CO 2 + P Other gases  KPa = P O KPa KPa KPa  P O 2 = KPa – (79.1 KPa KPa KPa)  P O 2 = 21.2 KPa

If a gas contains.4 moles oxygen,.3 moles of nitrogen,.2 moles of hydrogen, and.1 moles of argon, what is the partial pressure due to nitrogen?

 Eudiometer Lab Write the chemical equation that occurs when magnesium reacts with hydrochloric acid Will collect the gas that goes through the water Gas collected = H 2 + H 2 O vapor To find the pressure of the H 2, we need to subtract the pressure water vapor

 Diffusion:  Molecules move toward areas that are less concentrated  Gas molecules scatter randomly  Gases do not diffuse at the same rate.  “Effusion” – refers to gases escaping through a small hole in the container Graham’s Law of Effusion  Molecules of small mass diffuse faster than molecules of large mass  If two objects with different masses have the same kinetic energy the lighter object moves faster.

 Graham’s Law states that: The rate of effusion of a gas is inversely proportional to the square root of the gas’s molar mass

 Find the relative rates of diffusion for the gases krypton and bromine.  Find the relative rates of diffusion for the gases hydrogen and nitrogen.

 Hydrogen gas diffuses times faster than gas A. What is the molar mass for gas A and what is gas A?