1. Applying Your Knowledge  Identify the phase changes in Figure 3-2 that are labeled a, b, and c.  Interpreting Graphics Describe the two phase changes represented in Figure 3-2 that can happen to a liquid.  Applying Concepts Which three phase changes in Figure 3-2 are endothermic?

2. Science Starter  Write on a piece of paper: Setting (leave room to answer) Characters (leave room to answer) Action (leave room to answer)  Read the Red Herring story below and fill in the blanks. Then write down 3 yes or no questions to ask me to solve the mystery.  STORY – Out for a drive, he stopped for gas, but when he filled up, the fuel indicator never budged. Why not?

3. EQ: “How are the volume, temperature, and pressure of gases related?” Gases Video

4. What measurements are important when studying gases?  Volume The amount of space that matter fills. Measured in cm3, mL, or L Since gas particles move and fill the space available, the volume of the gas is the same as the volume of its container.

5. What measurements are important when studying gases?  Temperature Temperature is a measure of the average energy of random motion of the particles of a substance. The faster the particles move – the greater the energy and the higher the temperature.

6. What measurements are important when studying gases?  Pressure Pressure of a gas is the force of its outward push divided by the area of the walls of the container. Measured in units of pascals (Pa or kPa) Pressure= Force Area Gas Volume & Pressure Video

7. Boyle’s Law

8.  1600’s, Boyle measured the volumes of gases at different pressures.  He found that when the pressure of a gas (at constant temperature) is increased, the volume of the gas decreases. When the pressure is decreased, the volume increases.  This relationship between pressure and volume of gas is called Boyle’s Law  Boyle’s Law Video Boyle’s Law Video

10. Practice  A machine exerts a force of 252 N on a piston having an area of 0.430 m2. What is the pressure on the piston in Pa?  Pressure= 252N 0.430 m2 = 586 Pa N= neutons (measures force) Pa=pascals (measures pressure)

11. Volume and Temperature  Jacques Charles (1700’s) found that when the temperature of a gas is increased at constant pressure, its volume increases.  When the temperature of a gas is decreased at constant pressure, its volume decreases.  This principle is called Charles’s Law  Simple Gas Law Video Simple Gas Law Video

13. Pressure and Temperature  When the temperature of a gas at constant volume is increased, the pressure of the gas increases.  When the temperature is decreased, the pressure of the gas decreases.

14. Boyle’s Law Application  What is the unit used for pressure? What is the pressure when the volume is 0.5 L? What is the pressure when the volume is 1.0 L?

15. Boyle’s Law Application  How would the graph change if the volume of the cylinder remained constant and temperature was the manipulated variable?

16. Boyle’s Law Application  Compare the collisions between particles of gas and the walls of a container when the volume of gas is 1.0 L and when the volume is 2.0 L. Assume the number of particles does not change. Explain any differences in collisions.

17. Boyle’s Law Application  If P 1 is p1 kPa and P 2 is p2 kPa, what are V 1 and V 2 ?

18. Summarizer EQ: “How are the volume, temperature, and pressure of gases related?”