Chapter 7,Lesson 3: The Behavior of Gases EQ: How are the forces between particles different in solids, liquids, and gases? October 16, 2012 ISN page 53

Kinetic Molecular Theory Matter made of small particles Particles in constant random motion Particles collide with each other and their container Energy not lost in the collisions

Gases behave different than solids and liquids.  Affected by changes in Temperature Pressure Volume

Pressure Force per unit area Inverse relationship between pressure and volume at constant temperature  Lower volume = higher pressure and vice versa html.rincondelvago.com

Boyle’s Law At a constant temperature: V 2 =P 1 V 1 /P 2 Example: What is the final volume of a gas if the initial volume was 500 mL and the pressure increased from 200 kPa to 400 kPa  V 2 =200 kPa x 500 mL/400 kPa  V 2 =100000/400=250 mL

Boyle’s Law, cont. Real life: airplane ear pain = lower air pressure at altitude and the volume in your inner ear tries to increase. Ouch! tutorvista.com

Temperature and gases Low temperature = low volume Increases to temp  increases in volume Charles’s Law: volume of gas increases as temp increases if pressure is constant  V 1 /T 1 = V 2 /T 2

Charles’s Law, cont. Example: A sample of helium gas has a volume of 50 mL at 300 degrees K. At what temperature would the gas have a volume of 70 mL?  V 1 /T 1 =V 2 /T 2  50 mL/300 K = 70 mL/T 2  (300 K x 70 mL)/50 mL = 420 K

ISN page 52 Design a concept bookmark or t-shirt, front and back, one side showing Charles’s Law and the other showing Boyle’s Law. Include a paragraph describing each side of the bookmark or t-shirt. Remember to use COLOR!

Figure 18!!! Thoughts to ponder:  1. What is the slope of the line?  2. What is the reason for multiple lines?  3. What do the dashed lines represent?