1. Ideal Gas Law

2. PV = nRT P = pressure (in atm) V = volume (in L) n = moles
R = Universal Gas Constant ( L•atm / mol•K )
T = temperature (in Kelvin)

3. PV = nRT
At 25°C and 785 torr, how many moles of hydrogen will occupy 100. L?
n = 4.22 moles
What is the volume occupied by 9.45 g of acetylene (C2H2) at 2.61 atm and 303 K?
V = 3.46 L

4. PV = nRT
A 85.5 g sample of gas occupies 95.0 L at STP. What is the molecular weight of this gas?
N= 4.24 moles g
1.089 g of a gas occupies 4.50 L at 20.5C and atm. What is its molar mass?

5. Density = PM/RT What is the density of helium at 2.15 atm and -45ºC?
d = g/L
Calculate the density, in grams/L of I2 at 785 mm Hg and 215 K
14.57 g/L

6. Summary PV = nRT “Normal” problems Molar Mass problems
Density problems