Ideal Gas Laws What causes gas pressure in a closed container? What factors effect the pressure of an enclosed gas?

Day 1: What is an Ideal Gas? No gas behaves exactly like an ideal gas but it is a good model for making predictions. The Kinetic Theory of Matter (all matter is made of tiny, moving particles) explains the behavior of gasses. An ideal gas: Particles in a gas are in constant and random motion. The motion of one particle is unaffected by another unless they collide. Forces of attraction among particles can be ignored under ordinary conditions.

Day 1: Gas and Pressure Pressure is the result of force distributed over an area. Collisions between particles of a gas and the walls of the container cause the pressure in a closed container. The more frequent the collisions, the greater the pressure of the gas.

Day 2: Factors That Effect Pressure Temperature of a gas will ____________ its pressure. __________ the volume of a gas will increase its pressure _________ the number of particles in a gas will increase the pressure of the gas. increase Reducing Increasing

Day 2: Problem 1. Use the diagram below to determine how much does pressure goes up when the volume is decreased by one-half? One-Third?

Day 2: Answer When volume decrease by one-half pressure increase by two times. When volume decrease by one-third pressure increases by 3/2 times. (Inverse relationship)

Day 3: Gas Laws Charles Law states that the volume of a gas is directly proportional to its temperature, when pressure and the number of particles in a gas is held constant. Boyle’s Law states that the volume of a gas is inversely proportional to its pressure when temperature and the number of particles is held constant P1V 1 = P2V2

Day 3: Combined Gas Law Combined Gas Law (where n = the number of gas particles.)

Day 3: Problems Use the Gas Laws to graph the following relationships. Pressure Volume Temperature Volume

Day 4: Review 1. Use the kinetic theory of matter to explain why the pressure of a gas increases when its temperature increases? 2. If temperature doubles what happens to volume if everything else stays constant? Which of the gas laws applies in this case? 3. If volume doubles what happens to pressure if everything else stays constant? Which of the gas laws do you use in this case? 4. If the number of particles doubles in a gas what happens to the pressure? Which law did you use?

Day 4: Answers 1. As the molecules or atoms in the gas are heated they move faster, spread out and collide more often with the sides of the container increasing the pressure on the container. 2. According to Charles's Law temperature volume will double if temperature doubles. 3. According to Boyle’s Law pressure will decrease by half if volume doubles. 4. The pressure will double according to the Combined Gas Law.

Day 5: Quiz (Pressure!)