Mass to Mass Practice Key

Stoich Practice Name: KEN Hour: A correctly balanced equation and all work must be shown! 1. Copper (II) oxide decomposes into copper and oxygen gas. What mass of copper will be produced by the decomposition of 120.5 1   g CuO? 2CuO(s) --> 2Cu(s) + O2(g) 120.5 g CuO | 1 mol CuO | 2 mol Cu | 63.55 g Cu | 79.55 g CuO | 2 mol CuO | 1 mol Cu = 96.26 g Cu 2. Ammonia (NH3) is produced by the reaction of nitrogen gas and hydrogen gas. How much ammonia will be produced if 22.0 g of hydrogen gas react with excess nitrogen gas? N2(g) + 3H2(g) --> 2NH3(g) 22.0 g H2 | 1 mol H2 | 2 mol NH3 | 17.04 g NH3 | 2.02 g H2 | 3 mol H2 | 1 mol NH3 = 123.7 g NH3 3. The reaction of sodium and water produces sodium hydroxide and hydrogen gas. What mass of hydrogen gas is produced if 17.54 g of NaOH is produced by the reaction? 2 Na(s) + 2 H₂O(l) → 2 NaOH(aq) + H₂(g) 17.54 g NaOH | 1 mol NaOH | 1 mol H₂ | 2.02 g H₂ | 40 g NaOH | 2 mol NaOH | 1 mol H₂ = 0.44 g H₂ 4. The combustion of acetic acid (HC₂H₃O₂) produces carbon dioxide and water. What mass of carbon dioxide will be produced from the combustion of 25.0 g of acetic acid? HC₂H₃O₂(l) + 2 O₂(g) → 2 CO₂(g) + 2 H₂O(l) 25.0 g acetic | 1 mole acetic | 2 mol CO₂ | 44 g CO₂ | 60.06 g acetic | 1 mole acetic | 1 mol CO₂ = 36.63 g CO₂ 5. 20.0 g of iron (III) sulfide was prepared by heating iron and excess sulfur. What mass of iron was used in the preparation? 2 Fe(s) + 3 S(s) → Fe₂S₃(s) 20.0 g Fe₂S₃ | 1 mol Fe₂S₃ | 2 mol Fe | 55.85 g Fe | 207.91 g Fe₂S₃ | 1 mol Fe₂S₃ | 1 mol Fe = 10.75 g Fe