Chemistry Daily 10’s Week 14

1 1. For the reaction represented by the equation CH4 + 2O2  CO2 + 2H2O, how many moles of carbon dioxide are produced from the combustion of 100. g of methane? a. 6.23 mol b. 10.8 mol c. 12.5 mol d. 25 mol

2. For the reaction represented by the equation Pb(NO3)2 + 2KI  PbI2 + 2KNO3, how many moles of lead(II) iodide are produced from 300. g of potassium iodide and an excess of Pb(NO3)2? a. 0.904 mol b. 1.81 mol c. 3.61 mol d. 11.0 mol

2 1. For the reaction represented by the equation Cl2 + 2KBr  2KCl + Br2, how many grams of potassium chloride can be produced from 300. g each of chlorine and potassium bromide? a. 98.7 g b. 111 g c. 188 g d. 451 g

2. A chemist interested in the efficiency of a chemical reaction would calculate the a. mole ratio. b. energy released. c. percentage yield. d. rate of reaction.

3 1. If the percentage yield is equal to 100%, then a. the actual yield is greater than the theoretical yield. b. the actual yield is equal to the theoretical yield. c. the actual yield is less than the theoretical yield. d. there was no limiting reactant.

2. For the reaction represented by the equation Cl2 + 2KBr  2KCl + Br2, calculate the percentage yield if 200. g of chlorine react with excess potassium bromide to produce 410. g of bromine. a. 73.4% b. 82.1% c. 91.0% d. 98.9%

4 1. What is the maximum possible amount of product obtained in a chemical reaction? a. theoretical yield b. percentage yield c. mole ratio d. actual yield

2. For the reaction represented by the equation SO3 + H2O  H2SO4, how many grams of sulfuric acid can be produced from 200. g of sulfur trioxide and 100. g of water? a. 100. g b. 200. g c. 245 g d. 285 g

5 1. After calculating the amount of reactant B required to completely react with A, then comparing that amount with the amount of B available, one can determine the a. limiting reactant. b. rate of the reaction. c. energy released in the reaction. d. pathway of the reaction.

2. For the reaction represented by the equation 2Na + 2H2O  2NaOH + H2, how many grams of hydrogen are produced if 120. g of sodium and 80. g of water are available? a. 4.5 g b. 45 g c. 80. g d. 200 g

Answers & Standards 1.1. ANS: A STA: SC2.d 1.2. ANS: A STA: SC2.d 2.1. ANS: C STA: SC2.d 2.2. ANS: C STA: SC2.e 3.1 ANS: B STA: SC2.e 3.2. ANS: C STA: SC2.e 4.1. ANS: A STA: SC2.e 4.2 ANS: C STA: SC2.d 5.1. ANS: A STA: SC2.e 5.2. ANS: A STA: SC2.d