CHEMISTRY QUIZ #7

  1. Reaction stoichiometry involves: A. amounts of reactants and products B. the mass of a single reactant or product C. the temperature change during the reaction D. the types of bonds in a reaction.
  2. Fewer steps are required to solve stoichiometry problems when the reactant is given in: A. grams and the product is sought in grams B. moles and the product is sought in moles C. grams and the product is sought in liters D. liters and the product is sought in number of atoms
  3. The substance that restricts the participation of other reactants in a chemical reaction is known as the: A. limiting reactant B. limiting product C. excess reactant D. excess product e. party pooper
  4. The limiting reactant can be used to calculate the: A. actual yield B. theoretical yield C. experimental yield D. fractional yield
  5. Theoretical yield can ______be obtained in an experiment. A. sometimes B. always C. never D. usually
  6. The excess reactant when a fuel is burned is: a. the fuel b. CO2 c. O2 d. H2O

For the following, you will receive 2pts for a complete table, 1 pt for work, 1pt for correct answer, 1 pt for correct units, and 1pt for correct significant figures.

Mass-Mass Stoichiometry

7-12. What mass in grams of sodium hydroxide is produced if 20.0g of sodium metal are reacted with excess water according to the chemical equation 2 Na (s) + 2 H2O (l)  2 NaOH (aq) + H2 (g)?

Mole-Mass Stoichiometry

13-18. How many grams of ammonia sulfate can be produced if 30.0 mol of H2SO4 are reacted with excess NH3 according to the equation: 2 NH3 (aq) + H2SO4 (aq)  (NH4)2SO4 (aq) ?

Density Stoichiometry

19-24. How many liters of water can be produced if 250. mol of O2 are reacted with excess hydrogen according to the equation: 2 H2 (g) + O2 (g)  2 H2O (l) ? (Hint: The density of water is 1.00 g/mL)

Limiting Reactant

25-30. If 40.0 g of HCl and 15.0 g of Al(OH)3 react according to the equation 3HCl (aq) + Al(OH)3 (aq)  AlCl3 (aq) + 3 H2O (l), how many grams of water will be produced?

31-36. How many grams of chlorobenzene are produced when 100.g of benzene reacts with 100.g of chlorine gas according to the reaction shown on the board?

Percent Yield

37-42. When 150.g of ZnS are burned in excess oxygen, 68.5 g of ZnO are produced according to the equation 2 ZnS (s) + 3 O2  2 ZnO (s) + 2 SO2. What is the percent yield for this reaction?

43-48. The production of the fertilizer urea, CO(NH2)2, has a 78.1% yield. How many grams of urea are produced if 800.g NH3 react with excess CO2 according to the equation 2 NH3 (g) + CO2 (g)  CO(NH2)2 (s) + H2O (l) ?

49. How many grams of urea are produced if there is a 70% yield?

50. How many moles of urea are produced if there is a 70% yield?

EXTRA CREDIT:

51. Do all reactions have a limiting reactant? Explain.

52. What value is needed to convert mass to volume in a stoichiometry problem?

53. Hydrogen gas can be produced by adding an active metal, such as zinc, to hydrochloric acid. A student reports that for every kilogram of zinc reacted, 1.0 kg of hydrogen gas is evolved. Is this correct? Explain why or why not.

54. Write the balanced chemical equation for the combustion of methane that produces carbon dioxide and water.

55. Write the balanced equation for the reaction between baking soda (NaHCO3) and vinegar (HC2H3O2).