1. Gas Laws A series of equations that describe the behavior of a sample of gas.

2. Boyle’s Law http://group.chem.iastate.edu/Greenbowe/secti ons/projectfolder/flashfiles/gaslaw/boyles_law_ graph.html

3. Boyle’s Law First stated by Robert Boyle. The volume of a sample of gas is inversely proportional to the pressure, at constant temperature.

4. As pressure increases, volume decreases. Pressure VOLUMEVOLUME

5. When the inverse of the volume is graphed against pressure, a straight line is obtained. Equation for the line and Boyle’s law: PV = k Where P is pressure, V is volume, and k is the proportionality constant. 1V1V

6. Boyle’s Law :PV = k For a given sample of gas: Condition 1:Condition 2: P 1 V 1 = kP 2 V 2 = k Because k is the same we can rewrite this as: P 1 V 1 = P 2 V 2

7. P 1 V 1 = P 2 V 2 A tire has a volume of 67.3 L at a pressure of 3.0 atm. What would the volume be if the pressure were increased to 3.5 atm?

8. P 1 V 1 = P 2 V 2 A sample of gas has a volume of 74.3 mL at a pressure of 106.8 kPa. What would the pressure be if the volume is increased to 113.5 mL?

9. Charles’ Law Chemistry

10. Charles’ Law FFirst stated by Jacque Charles in the 1800s. TThe volume of a sample of gas is directly proportional to the thermodynamic temperature, at constant pressure.

11. As temperature increases, volume increases. Equation for the line (and Charles’ Law) V = k T Where V is volume, T is temperature, and k is a proportionality constant. Temperature VOLUMEVOLUME

12. The kelvin temperature scale must be used for all gas law problems. The size of a degree kelvin is the same as the size of a degree Celsius. K = C + 273 Celsius Kelvin

13. At what temperature would a gas have no volume? TTheoretically this would happen at absolute zero, or the temperature where all molecular motion stops. RRealistically, this does not happen. When gases are cooled down enough, they condense to liquids. Liquids do have volumes.

14. Charle’s Law :V/T = k For a given sample of gas: Condition 1:Condition 2: V 1 = kV 2 = k T 1 T 2 Because k is the same we can rewrite this as: V 1 = V 2 T 1 T 2

15. V 1 = V 2 T 1 T 2 A 12.3 L sample of helium fills a weather balloon at 20.0 o C. What would the volume change to if the weather balloon cooled to -12.0 o C as it rose in the atmosphere?

16. V 1 = V 2 T 1 T 2 A sample of methane occupies 445.9 mL at 75. o C. At what temperature would it have a volume of 323.8 mL?

17. Combined Gas Law RRelates the pressure, temperature and volume of a sample of gas. IIt is a combination of Boyle’s Law and Charles's Law. P 1 V 1 = P 2 V 2 T 1 T 2

18. P 1 V 1 = P 2 V 2 T 1 T 2 A helium balloon has a volume of 8.09 L at STP. What volume would it have as it rose in the atmosphere if the pressure decreased to 89.7 kPa and the temperature decreased to -10 o C?

19. Gay Lussac’s Law  In a constant volume, the pressure of a sample of gas is directly proportional to the thermodynamic temperature.  Equation: P 1 = P 2 T 1 T 2

20. A sample of gas at 1.0 atm of pressure at 25 C is heated to 378 C, what is the resulting pressure?

21. Charles’ Law V T Const P Boyle’s Law V P Const T Gay Lussac’s Law T P Const V Combined Gas Laws P, V, & T V 1 = V 2 T 1 T 2 P 1 V 1 = P 2 V 2 T 1 T 2 P 1 = P 2 T 1 T 2 P 1 V 1 = P 2 V 2