SOLVED

21) If the density of ethanol, C2H5OH, is 0.789 g/mL. How many milliliters of ethanol are needed to produce 20.0 g of CO2 according to the following chemical equation? C2H5OH(l) + 3 O2(g) → 2 CO2(g) + 3 H2O(l) A) 8.26 mL B) 13.3 mL C) 26.5 mL D) 53.1 mL 22) Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg(s) + (g) → 2MgO(s) When 3.00 g of magnesium burns, the theoretical yield of magnesium oxide is ________ g. A) 3.00 B) 4.98 C) 0.123 D) 2.49 E) 10.0 23) If the percent yield for the following reaction is 65.0%, how many grams of KClO3 are needed to produce 42.0 g of O2? 2 KClO3(s) → 2 KCl(s) + 3 O2(g) A) 69.7 g B) 107 g C) 165 g D) 371 g 24) If the percent yield for the following reaction is 75.0%, and 25.0 g of NO2 are consumed in the reaction, how many grams of nitric acid, HNO3(aq) are produced? 3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g) A) 17.1 g B) 22.8 g C) 30.4 g D) 38.5 g 25) Determine the theoretical yield of H2S (in moles) if 16 mol Al2S3 and 16 mol H2O are reacted according to the following balanced reaction. A possibly useful molar mass is Al2S3 = 150.17 g/mol. Al2S3(s) + 6 H2O(l) → 2 Al(OH)3(s) + 3 H2S(g) A) 48 mol H2S B) 16 mol H2S C) 32 mol H2S D) 24 mol H2S E) 8.0 mol H2S 26) Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li(s) + (g) → N(s) In a particular experiment, 1.00-g samples of each reagent are reacted. The theoretical yield of lithium nitride is ________ g. A) 1.01 B) 0.84 C) 5.0 D) 1.67 E) 2.50 27) Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO(s) + O(l) → (s) A 5.00-g sample of CaO is reacted with 4.83 g of O. How many grams of water remain after the reaction is complete? A) 0.00 B) 0.00991 C) 3.22 D) 1.04 E) 0.179 28) Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO(s) + O(l) → (s) In a particular experiment, a 5.50-g sample of CaO is reacted with excess water and 6.77 g of is recovered. What is the percent yield in this experiment? A) 123 B) 1.23 C) 7.91 D) 93.1 E) 81.3 29) Sodium metal and water react to form hydrogen and sodium hydroxide. If 17.94 g of sodium react with water to form 0.78 g of hydrogen and 31.20 g of sodium hydroxide, what mass of water was involved in the reaction? A) 14.04 g B) 17.94 g C) 30.42 g D) 31.98 g 30) Which substance is the limiting reactant when 8.0 g of sulfur reacts with 12 g of oxygen and 16 g of sodium hydroxide according to the following chemical equation: 2 S(s) + 3 O2(g) + 4 NaOH(aq) → 2 Na2SO4(aq) + 2 H2O(l) A) S(s) B) O2(g) C) NaOH(aq) D) None of these substances is the limiting reactant. 31) When 8.00 × 1022 molecules of ammonia react with 7.00 × 1022 molecules of oxygen according to the chemical equation shown below, how many grams of nitrogen gas are produced? 4 NH3(g) + 3 O2(g) → 2 N2(g) + 6 H2O(g) A) 1.86 g B) 2.17 g C) 4.88 g D) 7.44 g 32) When silver nitrate reacts with barium chloride, silver chloride and barium nitrate are formed. How many grams of silver chloride are formed when 10.2 g of silver nitrate reacts with 15.0 g of barium chloride? A) 8.61 g B) 9.40 g C) 12.1 g D) 18.8 g 33) When 14.0 g of calcium metal is reacted with water, 5.00 g of calcium hydroxide is produced. Using the following balanced equation, calculate the percent yield for the reaction? Ca(s) + 2 H2O(l) → Ca(OH)2(aq) + H2(g) A) 9.67% B) 19.3% C) 35.7% D) 66.0% 34) 8.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below. Which one of the following statements is false? N2(g) + 3 H2(g) → 2 NH3(g) A) 3.3 g of hydrogen are left over. B) Hydrogen is the excess reactant. C) Nitrogen is the limiting reactant. D) The theoretical yield of ammonia is 15 g. 35) 9.0 g of iron is reacted with 9.0 g of water according to the chemical equation shown below. Which one of the following statements is false? 3 Fe(s) + 4 H2O(l) → Fe3O4(s) + 4 H2(g) A) 12.4 g of Fe3O4 are produced. B) 5.13 g of H2O are left over. C) Mass is conserved in this reaction. D) Water is the limiting reactant.