More Stoichiometry Examples

  1. Ammonium fluoride reacts with calcium nitrate to produce calcium fluoride, dinitrogen monoxide, and water. If 22.8 g of ammonium fluoride react with 38.2 g of calcium nitrate, how much dinitrogen monoxide could be formed?
  2. Copper reacts with nitric acid to form copper (II) nitrate, nitrogen dioxide, and water. If 25.0 grams of copper react with an excess of nitric acid to form 7.24 grams of nitrogen dioxide, what is the percent yield of the reaction?
  3. Aluminum sulfide reacts with water in a double displacement reaction. If 56.0 g of aluminum sulfide reacts with 48.2 g of water, which is the excess reactant and how much of this reactant would be leftover after the reaction is complete?
  4. Calcium combines with nitrogen to form calcium nitride. If 33.8 g of calcium reacts with 20.4 g of nitrogen gas, which reactant is the limiting reactant? How much calcium nitride is formed? How much of the excess reactant is leftover?
  5. Dinitrogen tetroxide reacts with dinitrogen tetrahydride to form nitrogen gas and water. How much of each reactant is required to form 100.0 pounds of nitrogen gas?
  6. Silver tarnishes in the presence of dihydrogen sulfide (which smells like rotten eggs) and oxygen. The two products of the reaction are silver sulfide and water. How many grams of silver sulfide can be formed from a mixture of 1.1 grams of silver, 0.14 grams of hydrogen sulfide, and 0.080 grams of oxygen?
  7. An astronaut excretes about 2500 grams of water a day. Lithium oxide is used in spaceships to absorb this water; the single product of the reaction is lithium hydroxide. How many kilograms of lithium oxide must be carried for a 30-day space voyage for three astronauts?
  8. Oxygen masks for producing oxygen in emergency situations contain potassium superoxide (KO2), which reacts with water and carbon dioxide to form potassium hydrogen carbonate and oxygen gas. If a person wearing such a mask exhales 0.85 grams of carbon dioxide every minute, how many moles of potassium superoxide are consumed in 10.0 minutes? How many grams of oxygen are produced in 1.0 hours?
  9. Iron reacts with copper(II) sulfate to form copper metal and iron(II) sulfate. If a solution containing 400. grams of copper sulfate reacts with an excess amount of iron and 151 grams of iron (II) sulfate are obtained, what is the percent yield of the experiment?
  10. When 12.82 grams of a mixture of potassium chlorate and sodium chloride are heated, the potassium chlorate decomposes to form potassium chloride and oxygen gas. (This is an easy way to produce oxygen gas in the laboratory.) The sodium chloride does not undergo any reaction. After heating, the mass of residue (potassium chloride and sodium chloride) is 9.45 grams. Assuming that all of the mass lost represents a loss of oxygen gas, and that all of the potassium chlorate decomposes, calculate the percent of potassium chlorate in the mixture.
 

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