1. Density of a Gas at STP Lesson # 4

2. 1.Calculate the density of N 2 at STP. Assume that you have 1 mole of N 2 22.4 L 28.0 g =1.25 g/L litre grams Density=

3. 2.Calculate the density of CO 2 at STP. Assume that you have 1 mole of CO 2 22.4 L 44.0 g =1.96 g/L litre grams Density=

4. 3.Calculate the molar mass of gas that weighs 0.2668 g and has a STP molar volume of 175.7 mL. If the gas can be found in Harrison Hot Spring water, determine the gas. x 1 L 175.7 mL=0.0078438 mol mole grams Molar Mass= 1000 mL x 1 mol 22.4 L 0.0078438 mol 0.2668 g Molar Mass= =34.01 g/mol=H2S=H2S

5. 4.Calculate the volume of O 2 gas produced at STP for the complete decomposition of 12.5 g HgO if the yield is 45.0 %. 2HgO → 2Hg+O 2 = 0.291 L x 0.450 1 mole x 22.4 L x 1 mole O 2 2 mole HgO x 1mole12.5 g HgO 216.6 g 12.5 g? L 1212

6. 5.Calculate the theoretical yield in litres at STP of CO 2 in the reaction of 100. g of Fe 2 O 3. If the actual yield was 19.0 L @ STP, calculate the percentage yield. 2Fe 2 O 3 +3C  4Fe+3CO 2 100. g Fe 2 O 3 x 1 mole x 3 mole CO 2 x 22.4 L = 21.0 L 159.6 g 2 mole Fe 2 O 3 1 mole Percentage yield = 19.0 L x 100% = 90.3 % 21.05 L 3232 100. g ? L 19.0 L