Back Print Lesson Name Class Date Assessment Quiz Section: Calculating Quantities in Reactions In the space provided, write the letter of the term or phrase that best answers the question. ______ 1. The chemical equation P4O10 6H2O £ 4H3PO4 can be correctly interpreted as a. 1 molecule of P4O10 6 molecules of H2O form 4 molecules of H3PO4. b. 1 mol P4O10 6 mol H2O reacts to form 4 mol H3PO4. c. 1 g P4O10 6 g H2O produces 4 g H3PO4. d. Both (a) and (b) ______ 2. Stoichiometry is the branch of chemistry that deals with the between elements and compounds as reactants and products in a chemical reaction. a. bonding b. energy transfers c. numerical relationship d. physical interactions ______ 3. How many mole ratios can be correctly obtained from the following chemical equation? Na2S Cd(NO3)2 £ 2NaNO3 CdS a. b. c. d. 1 4 12 16 ______ 4. Molar mass can be used to relate a. mass of reactant to moles of reactant. b. moles of product to mass of product. c. mass of product to moles of product. d. All of the above ______ 5. In the chemical reaction described by the equation 4Fe(s) 3O2(g) £ 2Fe2O3(s), the mole ratio of iron(III) oxide to iron is a. 1:1. b. 1:2. c. 2:3. d. 4:1. Copyright © by Holt, Rinehart and Winston. All rights reserved. Holt Chemistry 48 Stoichiometry Back Print Lesson Name Class Date Quiz continued 1 ______ 6. The expression mass has the unit molar mass 2 a. mol /g. b. g/mol2. c. mol. d. g. ______ 7. In the chemical equation wA xB £ yC zD, if one knows the mass of A and the molar masses of A, B, C, and D, one can determine a. the mass of each reactant and product. b. the mass of B only. c. the total mass of C and D only. d. the total mass of A and B only. 1 ______ 8. The expression volume has the unit molar volume a. g/L. c. mol. b. L. d. mol/L. ______ 9. What could you use to calculate the volume of ammonia gas produced by the reaction of 2.0 L of nitrogen gas in excess hydrogen gas at non-STP conditions according to the chemical equation below? N2(g) 3H2(g) £ 2NH3(g) a. b. c. d. one density, one molar mass, and one mole ratio. one density, two molar masses, and one mole ratio. two densities, two molar masses, and one mole ratio. two densities, two molar masses, and two mole ratios. ______10. If, in the reaction C5H12(l) £ C5H8(l) 2H2(g), 1.50 1022 molecules of C5H12 decompose, then the following expression 1 mol C5H12 1.50 1022 molecules C5H12 6.022 1023 molecules C5H12 2.02 g H 2 mol H2 2 1 mol H2 1 mol C5H12 calculates the a. number b. moles of H2 molecules produced. c. mass d. volume Copyright © by Holt, Rinehart and Winston. All rights reserved. Holt Chemistry 49 Stoichiometry Back Lesson Print TEACHER RESOURCE PAGE Answer Key Quiz—Section: Calculating Quantities in Reactions 1. 2. 3. 4. 5. d c c d b 6. 7. 8. 9. 10. 21. Thirty percent of the expected product is not produced. Therefore, thirty percent of the limiting reactant must be part of reverse or side reactions. 22. Moles are used because the coefficients in a balanced equation show the number of moles of reactants and products in the chemical reaction. 23. The equation does not show other components of air, such as nitrogen and organic compounds. It also does not show impurities in gasoline, such as compounds of nitrogen and sulfur. During combustion, these substances are also oxidized, producing pollutants such as nitrogen, sulfur oxides, and hydrocarbons. In addition, the equation does not show that incomplete combustion can occur, in which case carbon monoxide is also produced. 1 mol KClO3 24. 100. g KClO3 122.5 g KClO3 74.55 g KCl 2 mol KCl 1 mol KCl 1 mol KClO3 c a c c c Quiz—Section: Limiting Reactants and Percentage Yield 1. 2. 3. 4. 5. b d c c b 6. 7. 8. 9. 10. c a d d b Quiz—Section: Stoichiometry and Cars 1. 2. 3. 4. 5. b c c c c 6. 7. 8. 9. 10. d b a b b 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. d b a d a c c b d a 60.8 g KCl 1.961 g CO 1 L CO2 1 mol CO2 1 mol MgCO 3 44.01 g CO2 1 mol CO2 84.31 g MgCO 3 244 g MgCO3 1 mol MgCO3 25. 65.0 L CO2 2 Chapter Test 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. d d b d a c b a a a Copyright © by Holt, Rinehart and Winston. All rights reserved. Holt Chemistry 90 Stoichiometry