1. Chapter 10
Gas Laws

2. Air…
The atmosphere is

3. Diving Issues Nitrogen Narcosis
Nitrogen narcosis is a condition that occurs in divers breathing compressed air. When divers go below depths of approximately 100 ft, increase in the partial pressure of nitrogen produces an altered mental state similar to alcohol intoxication.

4. The Bends Decompression sickness
nitrogen from the air will dissolve in the water in his or her body. If the diver were to swim quickly to the surface, it is just like uncorking a bottle of soda -- the gas is released. This can cause a very painful condition, and it is sometimes fatal.

5. Increased pressure
The pressure on divers increases by one atmosphere for every 33 feet of depth
At 100 feet, some people say it is difficult to breathe

6. Decompression
If divers do not decompress as they surface, they can develop the bends.
Stops at various intervals as they rise to the surface, sometimes for 15 to 20 minutes or more.

7. Pressure
Defined as the
Equation:
Psi, kg/m2, etc

8. How is pressure measured?
Barometers
Manometers p 123, fig 5.2
Units:

9. Gas Properties Move The physical volume of the
Attractive/repulsive forces

10. Gas Properties Energy is
Average kinetic energy is related to the absolute temperature

11. The Gas Laws Boyle’s Charles’ Guy-Lussac’s Avogadro’s Combined Ideal
Molecular mass
Dalton’s partial pressures

12. Boyle’s
Relates
Equation:
Temperature and number of molecules fixed

13. Charles’ Relates Equation: Pressure and number of molecules fixed
If T increases, V increases
Temperature must be in Kelvins – if the Celsius scale is used, the ratio is not constant

14. Guy_Lussac’s Relates Equation Volume and number of molecules fixed
If T increases, P increases
Temp in Kelvin, not C

15. Avogadro’s Relates Equation Pressure and temp are fixed
Equal volumes of gases at the same P and T contain the same # molecules

16. Combined
Relates
Equation
Number of molecules is fixed

17. Ideal Gas Law Combines all of the above Equation:
Use Standard Temperature and Pressure, 1.00 atm, 273 K
P=Pressure, V=volume, n=number of moles, R=Gas law constant Latm/Kmol
R was found by setting 1 mole of gas at 1.00 atm and 273 K and 22.4 L and solving using ideal gas law

18. Molecular Mass Determine the molar mass of a gas n =
n=g/M
n = PV/RT manipulate the gas law
Also… in M = gRT/PV g/V is density in g/L

19. Dalton and Partial Pressure
Ptotal = P1 + P2 + …