Gas Laws

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

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

• Boyles
• Charles
• Guy-Lussacs
• Avogadros
• Combined

• Ideal
• Molecular mass
• Daltons partial pressures

12
Boyles

• Relates
• Equation
• Temperature and number of molecules fixed

13
Charles

• Relates
• Equation
• Pressure and number of molecules fixed

14
Guy_Lussacs

• Relates
• Equation
• Volume and number of molecules fixed

15
Avogadros

• Relates
• Equation
• Pressure and temp are fixed

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

18
Molecular Mass

• Determine the molar mass of a gas
• n
• n

19
Dalton and Partial Pressure

• Ptotal P1 P2