1. Gas Stoichiometry

2. Molar Volume What is the volume of 1 L of gas at STP? 22.414 L This volume of 1 L at STP is called the molar volume of a gas It is the same for all gases at STP

3. Example A sample of nitrogen has a volume of 1.75L at STP. How many moles of nitrogen are present?

4. Examples How many moles of air are there in a 2.0 L bottle at 19ºC and 747 mm Hg? What is the pressure exerted by 1.8 g of H 2 gas exert in a 4.3 L balloon at 27ºC?

5. Example Calcium oxide is produced by the thermal decomposition of calcium carbonate. Calculate the volume of carbon dioxide at STP produced from the decomposition of 152 g if calcium carbonate.

6. Example A 2.55g sample of ammonium nitrite decomposes into nitrogen gas and water vapor. What volume of nitrogen gas will be collected if the temperature is 26ºC and the total pressure is 745mmHg?

7. Gas Density g/L is density PV = nRT n/V = P/ RT M is molar mass nM/ V = PM/ RT nM is grams and g/ V is density d = PM/ RT M = dRT/ P

8. Example 3 What is the density of CO 2 at 745mmHg and 65ºC?

9. Example 4 A large flask is evacuated and weighed, its mass if found to be 134.567g. It is then filled with a gas to a pressure of 735mmHg at 31ºC and reweighed; its mass is 137.456g. It is filled with water and the volume of the water is measured to be 936 cm 3. What is the molecular weight of the gas?