1. Ideal Gas Law

2. Ideal Gas
Follows all gas laws under all conditions of temperature and pressure
Follows all conditions of the Kinetic Molecular Theory (KMT)
An ideal gas does not exist in real life

3. Real Gas
Follows some gas laws under some conditions of temperature and pressure
Does not conform to the Kinetic Molecular Theory. Real gases have a volume and attractive and repulsive forces
A real gas differs from an ideal gas the most at low temperature and high pressure

4. Ideal Gas law equation PV = nRT
P= pressure (atm, torr, mmHg, kPa) V= volume (L, mL) n = # of moles (mol) R = Ideal Gas Constant T = temperature in Kelvin (K, ˚C +273)

5. Ideal gas constant * Use the same unit as your given pressure
R = L atm = L kPa = 62.4 L mmHg = 62.4 L torr mol K mol K mol K mol K
* Use the same unit as your given pressure

6. Example 1
Calculate the number of moles of gas contained in a 3.00L vessel at 298K with a pressure of 1.50 atm.
V = 3.00L
T = 298K
P = 1.50atm
n = ?
R = L atm
mol K
PV=nRT
(1.50)(3.00) = n (0.0821) (298)
n= mol

7. Example 2
What will the pressure (in kPa) be when there are mol of gas in a 5.00L container at 17.0˚C?
V = 5.00L
T = 17.0˚C = 290K
P = ? kPa
n = mol
R = L atm
mol K
PV=nRT
P(5.00) = (0.400)(8.314) (290)
P= 193 kPa