Warmup 1/5/16
If we add more gas to a balloon, what changes?
To complete how we model an ideal gas
pp 481: 1, 2, 3, 4

Notes on Ideal Gas Law
We can now model almost any gas in any way, but we need to add one more piece.
We haven’t taken into account yet what happens if we simply change how much gas we have.

Notes on Ideal Gas Law
We can now model almost any gas in any way, but we need to add one more piece.
We haven’t taken into account yet what happens if we simply change how much gas we have.
If I imagine a balloon filled with gas, we can ask what happens if we pump more gas into it.

Notes on Ideal Gas Law
We can now model almost any gas in any way, but we need to add one more piece.
We haven’t taken into account yet what happens if we simply change how much gas we have.
If I imagine a balloon filled with gas, we can ask what happens if we pump more gas into it.
Either the pressure goes up, or the volume goes up.

Notes on Ideal Gas Law
This gives us all the pieces we need for the
Ideal Gas Law.
PV = nRT

Notes on Ideal Gas Law
This gives us all the pieces we need for the
Ideal Gas Law.
PV = nRT
Pressure in kPa volume in dm 3 number of moles gas constant (=8.31) temperature in K

Notes on Ideal Gas Law
Example: What is the pressure of 4.5 moles of a gas in a 198 dm 3 container at a temperature of
8 ° C?

Notes on Ideal Gas Law
Example: What is the pressure of 4.5 moles of a gas in a 198 dm 3 container at a temperature of
8 ° C?
PV = nRT P = nRT
V
P =
(4.5)(8.31)(273+8)
(198)
P = 53.1 kPa

Notes on Ideal Gas Law
Example: What is the pressure of 4.5 moles of a gas in a 198 dm 3 container at a temperature of
8 ° C?
PV = nRT P = nRT
V
P =
(4.5)(8.31)(273+8)
(198)
P = 53.1 kPa
The only thing to watch out for in practicing with this is your units. Make sure you have the units listed before this example problem.

Practicing Ideal Gas Law
One last practice set for the semester.
Turn to page 495 and do the following:
38, 39, 40, 41, 42, 43

Exit Question
Solve using the ideal gas law:
P=200 kPa, n=7 mol, T=327 K, V=?
a) 457,800 dm 3 b) 3,804,318 dm 3 c) 11.45 dm 3 d) 95.11 dm 3 e) 0 f) None of the above