Stoichiometry Problems

Use your knowledge of stoichiometry to solve the following problems. Show your work for all problems! Failing to show your work will make studying harder if not impossible!

1. Nitrogen Gas and Hydrogen Gas react to form Ammonia. (All reactants and products are gases).
   N₂ + 3H₂ → 2NH₃
   1. If you have 1 mol of nitrogen gas and 4 mol of hydrogen gas how many moles of ammonia form? If any reactant gases are leftover give the amount of each in moles that did not react.
   2. If you want to make 25 mol of ammonia, how much nitrogen and hydrogen gas do you need in moles?
   3. If you have 3 mol of nitrogen gas and 3 mol of hydrogen gas how many moles of ammonia form? If any reactant gases are leftover give the amount of each in moles that did not react.
   4. If you have 5.7 mol of nitrogen gas and 12.9 mol of hydrogen gas how many moles of ammonia form? If any reactant gases are leftover give the amount of each in moles that did not react.
   5. You have 12 mol nitrogen and an unlimited supply of hydrogen. How much ammonia can you make (in moles)?
   6. If you set out to make 15 mol of ammonia but the experiment only produces 12.5 moles, what is the percent yield?
2. Zinc and Hydrochloric Acid react to form Zinc Chloride and Hydrogen Gas.
   Zn + 2HCl → ZnCl₂ + H₂
   1. You want to make 0.75 mol of hydrogen gas. How many grams of zinc do you need to use?
   2. You have 10 mol zinc and 15 mol hydrochloric acid. How many moles of hydrogen gas can you make? If any reactants are leftover give the amount of each in moles that did not react.
   3. You have 130.8 g of zinc and 1 mol of hydrochloric acid. How many moles of hydrogen gas can you make? If any reactants are leftover give the amount in grams of each that did not react.
   4. When you perform the reaction as described in the previous question you collect 0.24 moles of hydrogen gas. What is the percent yield?

3. Benzene (C₆H₆) burns in oxygen to form carbon dioxide and water.
   2C₆H₆ + 15O₂ → 12CO₂ + 6H₂O
   1. If you burn 2 mol of benzene how much oxygen (in moles) is required to burn all of the benzene?
   2. How many moles of carbon dioxide result from the burning of 2 mol of benzene?
   3. How many moles of water result from the burning of 78.1 g of benzene?
   4. How many grams of carbon dioxide result from the burning of 156.2 g of benzene?
4. Elemental sulfur (S₈) reacts with fluorine gas to form sulfur hexafluoride.
   S₈ + 24F₂ → 8SF₆
   1. How many moles of fluorine gas are required to react with each mole of elemental sulfur?
   2. If you have 12 mol of fluorine gas and 2 mol elemental sulfur then how many moles of sulfur hexafluoride can you make? If any reactants are leftover give the amount of each in moles that did not react.
   3. If you have 2.4 mol of fluorine gas and 0.05 mol elemental sulfur then how many moles of sulfur hexafluoride can you make? If any reactants are leftover give the amount of each in moles that did not react.
   4. You have 128.25 g of elemental sulfur. How many grams of fluorine gas are required to react with all of the sulfur?
   5. You have 384.8 g of elemental sulfur. If you have more than enough fluorine gas to react with all of the sulfur then how many grams of sulfur hexafluoride can you make?
   6. When you carry out the reaction as described in the previous question you measure your product and find you have a 65% yield. How many grams of sulfur hexafluoride did you end up collecting?