1. Molar Volume and Density Problems

2. You can find the density of gases at STP using:
Density = formula mass (g/mole)
22.4 Liters/mole

3. What is the density of methane (CH4) at STP?
D= formula mass
22.4L
= 16 g = g/L
22.4 L

4. If the density of a gas is 1.25 g/L, what is the formula mass ?
1.25 g/L= formula mass
22.4L/mole
1.25 g x L = 28 g/mole
L mole

5. Which of the 7 diatomic elements has this density?

6. Calculate the density of ammonia.
1. Write the formula for ammonia.
2. Calculate the formula mass.
3. Use the formula D= M/V
NH3 = = 17 g/mole
D= 17 g/mole = g/ L
22.4 L/mole