General, Organic & Biological Chemistry, 5e (Timberlake) Chapter Chemical Reactions and Quantities 7.1 Multiple-Choice Questions 1) A chemical equation is balanced when A) the total number of molecules is the same in reactants and products B) the total number of ions is the same in reactants and products C) the sum of the coefficients of the reactants is equal to the sum of the coefficients of the products D) the number of atoms of each element is the same in reactants and products E) the charge on each atom is the same in reactants and products Answer: D Objective: 7.1 Global Outcomes: GO2 2) In any balanced chemical equation, the number of each type of atom on both sides of the equation is A) doubled B) the same C) decreased by one D) increased by one E) dependent on the temperature Answer: B Objective: 7.1 Global Outcomes: GO2 3) Which of the following gives the balanced equation for this reaction? K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + KNO3 A) KPO4 + CaNO3 + KNO3 B) K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + 3KNO3 C) 2K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + 6KNO3 D) 2K3PO4 + 3Ca(NO3)2 → Ca3(PO4)2 + 6KNO3 E) K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + KNO3 Answer: D Objective: 7.1 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 4) Which of the following correctly gives the best coefficients for the reaction below? N2H4 + H2O2 → N2 + H2O A) 1, 1, ,1 B) 1, 2, 1, C) 2, 4, 2, D) 1, 4, 1, E) 2, 4, 2, Answer: B Objective: 7.1 Global Outcomes: GO2 5) What coefficient is placed in front of O2 to complete the balancing of the following equation? C5H8 + ? O2 → 5CO2 + 4H2O A) B) C) D) E) Answer: D Objective: 7.1 Global Outcomes: GO2 6) What is the coefficient of hydrogen, H2, when the following equation is balanced? Al + H2SO4 → Al2(SO4)3 + ? H2 A) B) C) D) E) Answer: C Objective: 7.1 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 7) In this reaction, what is the coefficient for calcium oxide? CaO(s) + CO2(g) → CaCO3(s) A) B) C) D) E) Answer: A Objective: 7.1 Global Outcomes: GO2 8) In the following reaction, when the equation is correctly balanced, what is the correct coefficient for sodium chloride? Pb(NO3)2(aq) + NaCl(aq) → PbCl2(s) + NaNO3(aq) A) B) C) D) E) Answer: B Objective: 7.1 Global Outcomes: GO2 9) In the following reaction, when the equation is correctly balanced, what is the correct coefficient for H2? Fe(s) + HCl(aq) → FeCl3(aq) + H2(g) A) B) C) D) E) Answer: C Objective: 7.1 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 10) In the following reaction, when the equation is correctly balanced, what is the correct coefficient for aluminum chloride? Al(s) + Cl2(g) → AlCl3(s) A) B) C) D) E) Answer: B Objective: 7.1 Global Outcomes: GO2 Pentane (C5H12) reacts with oxygen (O2) to form carbon dioxide (CO2) and water (H2O) according to the following reaction Answer the question(s) that follow about this reaction C5H12 + ? O2 → ? CO2 + ? H2O 11) What is the coefficient for oxygen in the balanced equation? A) B) C) D) E) Answer: E Objective: 7.1 Global Outcomes: GO2 12) What is the coefficient for carbon dioxide in the balanced equation? A) B) C) D) E) Answer: C Objective: 7.1 Global Outcomes: GO2 13) What is the coefficient for water in the balanced equation? A) B) C) D) E) Answer: D Objective: 7.1 Global Outcomes: GO2 14) In a reaction, two or more elements or compounds form one product A) decomposition B) single replacement C) dehydration D) double replacement E) combination Answer: E Copyright © 2016 Pearson Education, Inc Objective: 7.2 Global Outcomes: GO2 15) The following reaction takes place when an electric current is passed through water It is an example of a reaction 2H2O → 2H2 + O2 A) combination B) single replacement C) dehydration D) decomposition E) double replacement Answer: D Objective: 7.2 Global Outcomes: GO2 16) What is the classification for this reaction? SO3 (g) + H2O (l) → H2SO4(l) A) decomposition B) combination C) replacement D) double replacement E) oxidation reduction Answer: B Objective: 7.2 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 17) The reaction of carbon with oxygen to produce carbon monoxide is an example of which class of reaction? 2C(s) + O2(g) → 2CO(g) A) single replacement B) double replacement C) combination D) catalytic E) endothermic Answer: C Objective: 7.2 Global Outcomes: GO2 18) What is the classification for this unbalanced reaction? Fe + HCl → FeCl3 + H2 A) dehydration B) combination C) decomposition D) single replacement E) double replacement Answer: D Objective: 7.2 Global Outcomes: GO2 19) The reaction of methane with oxygen to produce carbon dioxide and water is an example of which class of reaction? CH4(g) + 2O2(g) → CO2(g) + 2H2O(g) A) single replacement B) double replacement C) combination D) oxidation E) endothermic Answer: D Objective: 7.2 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 20) Which of the following is an oxidation-reduction reaction? A) CaCl2 + Na2SO4 → CaSO4 + 2NaCl B) KOH + HNO3 → H2O + KNO3 C) N2 + O2 → 2NO D) AgNO3 + NaCl → AgCl + NaNO3 E) Al2(SO4)3 + 6KOH → 2Al(OH)3 + 3K2SO4 Answer: C Objective: 7.3 Global Outcomes: GO2 21) What is oxidized and what is reduced in the following reaction? 2Al(s) + 3Br2(g) → 2AlBr3(s) A) Al is oxidized and Br2 is reduced B) AlBr3 is reduced and Br2 is oxidized C) Al is reduced and Br2 isoxidized D) AlBr3 is reduced and Al is oxidized E) AlBr3 is oxidized and Al is reduced Answer: A Objective: 7.3 Global Outcomes: GO2 22) Which of the following describes an oxidation reaction? A) loss of electrons or loss of oxygen B) loss of electrons or gain of oxygen C) loss of electrons or gain of hydrogen D) gain of electrons or gain of oxygen E) gain of electrons or loss of H Answer: B Objective: 7.3 Global Outcomes: GO2 23) In an oxidation-reduction reaction, the substance oxidized always A) takes on oxygen atoms B) shows a loss of electrons C) gives up hydrogen atoms D) shows a gain of electrons E) becomes a charged species Answer: B Objective: 7.3 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 24) In this reaction, what is the substance oxidized? Zn(s) + HCl(aq) → ZnCl2(aq) + H2(g) A) chlorine B) zinc chloride C) hydrogen D) zinc E) oxygen Answer: D Objective: 7.3 Global Outcomes: GO2 25) In an oxidation-reduction reaction, the substance reduced always A) takes on oxygen atoms B) shows a loss of electrons C) gives up hydrogen atoms D) shows a gain of electrons E) becomes a charged species Answer: D Objective: 7.3 Global Outcomes: GO2 26) How many moles of iron are present in 3.15 × 1024 atoms of iron? A) 5.23 moles B) 1.90 moles C) 292 moles D) 0.523 moles E) 1.90 × 1048 moles Answer: A Objective: 7.4 Global Outcomes: GO4 27) How many atoms of neon are present in 1.30 moles of neon? A) 3.15 × 1023 atoms B) 4.63 × 1023 atoms C) 7.83 × 1023 atoms D) 6.02 × 1023 atoms E) 7.83 × 1024 atoms Answer: C Objective: 7.4 Global Outcomes: GO4 Copyright © 2016 Pearson Education, Inc 28) One mole of particles of any substance contains how many particles? A) 106 B) × 10-10 C) × 1010 D) 6.02 × 1023 E) 6.02 × 10-23 Answer: D Objective: 7.4 Global Outcomes: GO4 29) Avogadro's number is the number of A) particles in mole of a substance B) amu in mole of a substance C) grams in mole of a substance D) moles in 6.02 × 1023 grams of an element E) moles in 6.02 × 1023 amu of an element Answer: A Objective: 7.4 Global Outcomes: GO4 30) How many molecules of water, H2O, are present in 75.0 g of H2O? A) 75.0 molecules B) 4.17 molecules C) 7.53 × 1024 molecules D) 2.51 × 1024 molecules E) 5.02 × 1024 molecules Answer: D Objective: 7.5 Global Outcomes: GO4 31) How many hydrogen atoms are present in 75.0 g of H2O? A) 75.0 atoms B) 4.17 atoms C) 7.53 × 1024 atoms D) 2.51 × 1024 atoms E) 5.02 × 1024 atoms Answer: E Objective: 7.5 Global Outcomes: GO4 Copyright © 2016 Pearson Education, Inc 32) The molar mass of potassium is A) 19 g B) 31.0 g C) 6.02 × 1023 grams D) 39.1 g E) 15g Answer: D Objective: 7.5 Global Outcomes: GO4 33) One mole of helium gas has a mass of A) 1.00 g B) 2.00 g C) 3.00 g D) 4.00 g E) 8.00 g Answer: D Objective: 7.5 Global Outcomes: GO4 34) How many moles of water, H2O, are present in 75.0 g of H2O? A) 4.41 moles B) 4.16 moles C) 75.0 moles D) 7.50 moles E) 1.35 × 103 moles Answer: B Objective: 7.5 Global Outcomes: GO4 35) 0.100 mole of lithium has a mass of A) 3.00 g B) 0.300 g C) 6.94 g D) 0.694 g E) 0.700 g Answer: D Objective: 7.5 Global Outcomes: GO4 36) Calculate the molar mass of potassium chloride, KCl A) 74.6 g B) 54.5 g C) 6.74 g D) 67.4 g E) 19.0 g Answer: A Objective: 7.5 Global Outcomes: GO4 37) What is the molar mass of copper(II) sulfate, CuSO4? A) 16.0 g B) 63.6 g C) 111.6 g D) 159.6 g E) 319.2 g 10 Copyright © 2016 Pearson Education, Inc For the question(s) that follow, consider the following balanced equation Mg3N2(s) + 6H2O(l) → 3Mg (OH)2(s) + 2NH3(g) 58) What is the correct form of the conversion factor needed to convert the number of moles of H2O to the number of moles of NH3 produced? A) B) C) D) E) Answer: A Objective: 7.6 Global Outcomes: GO4 59) When moles of Mg3N2 are allowed to react, how many moles of H2O also react? A) mole B) moles C) moles D) moles E) 12 moles Answer: E Objective: 7.6 Global Outcomes: GO4 For the question(s) that follow, consider the following equation 2Mg + O2 → 2MgO 60) How many grams of MgO are produced when 40.0 grams of O2 react completely with Mg? A) 30.4 g B) 50.4 g C) 60.8 g D) 101 g E) 201 g Answer: D Objective: 7.7 Global Outcomes: GO4 17 Copyright © 2016 Pearson Education, Inc For the question(s) that follow, consider the following balanced equation Mg3N2(s) + 6H2O(l) → 3Mg (OH)2(s) + 2NH3(g) 61) How many grams of H2O are needed to produce 150 g of Mg(OH)2? A) 46 g B) 18 g C) 130 g D) 93 g E) 23 g Answer: D Objective: 7.7 Global Outcomes: GO4 62) When 36.0 g of H2O react, how many grams of NH3 are produced? A) 34.0 g B) 10.0 g C) 5.67 g D) 11.3 g E) 102 g Answer: D Objective: 7.7 Global Outcomes: GO4 63) How many grams of hydrogen are needed to produce 1.80 g of water according to this equation? 2H2 + O2 → 2H2O A) 0.100 g B) 0.180 g C) 0.200 g D) 2.00 g E) 4.00 g Answer: C Objective: 7.7 Global Outcomes: GO4 18 Copyright © 2016 Pearson Education, Inc 64) In the reaction of silver nitrate with sodium chloride, how many grams of silver chloride will be produced from 100 g of silver nitrate when it is mixed with an excess of sodium chloride? The equation for the reaction is below AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq) A) 107.9 g B) 169.9 g C) 84.4 g D) 0.589 g E) 58.9 g Answer: C Objective: 7.7 Global Outcomes: GO4 65) Find the mass of AlCl3 that is produced when 25.0 grams of Al2O3 react with excess HCl according to the following equation Al2O3(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2O(l) A) 155 g B) 72.9 g C) 65.4 g D) 32.6 g E) 16.3 g Answer: C Objective: 7.7 Global Outcomes: GO4 66) How many grams of NO are required to produce 145 g of N2 in the following reaction? 4NH3(g) + 6NO(g) → 5N2(g) + 6H2O(l) A) 186 g B) 155 g C) 125 g D) 129 g E) 145 g Answer: A Objective: 7.7 Global Outcomes: GO4 19 Copyright © 2016 Pearson Education, Inc 67) How many grams of N2 are produced from 100 g of NH3 in the following reaction? 4NH3(g) + 6NO(g) → 5N2(g) + 6H2O(l) A) 165 g B) 132 g C) 125 g D) 206 g E) 7.35 g Answer: D Objective: 7.7 Global Outcomes: GO4 68) How many grams of CO2 are produced from 125 g of O2 and excess CH4? CH4 + 2O2 → CO2 + 2H2O A) 125 g of CO2 B) 62.5 g of CO2 C) 172 g of CO2 D) 85.9 g of CO2 E) 250 g of CO2 Answer: D Objective: 7.7 Global Outcomes: GO4 69) When 3.05 moles of CH4 are mixed with 5.03 moles of O2 the limiting reactant is CH4 + 2O2 → CO2 + 2H2O A) CH4 B) O2 C) CO2 D) H2O Answer: B Objective: 7.8 Global Outcomes: GO4 20 Copyright © 2016 Pearson Education, Inc 70) When 85.0 g of CH4 are mixed with 160 g of O2 the limiting reactant is CH4 + 2O2 → CO2 + 2H2O A) CH4 B) O2 C) CO2 D) H2O Answer: B Objective: 7.8 Global Outcomes: GO4 71) When 10.0 g of NH3 reacts, the actual yield of N2 is 8.50 g What is the percent yield? 4NH3(g) + 6NO(g) → 5N2(g) + 6H2O(l) A) 85.0% B) 51.5% C) 20.6% D) 41.3% E) 8.5% Answer: D Objective: 7.8 Global Outcomes: GO7 72) When 85.0 g of CH4 are mixed with 160 g of O2 what is the maximum amount of CO2 that can be produced? CH4 + 2O2 → CO2 + 2H2O A) 2.50 moles B) 5.00 moles C) 5.31 moles D) 7.81 moles Answer: A Objective: 7.8 Global Outcomes: GO4 21 Copyright © 2016 Pearson Education, Inc 73) When 60.0 g of CH4 reacts with excess O2, the actual yield of CO2 is 112 g What is the percent yield? CH4 + 2O2 → CO2 + 2H2O A) 53.6 % B) 187 % C) 67.9 % D) 46.4 % Answer: C Objective: 7.8 Global Outcomes: GO4 74) Find the mass of AlCl3 that is produced when 10.0 grams of Al2O3 react with 10.0 g of HCl according to the following equation Al2O3(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2O(aq) A) 16.2 g B) 20.0 g C) 12.2 g D) 10.0 g E) 6.10 g Answer: C Objective: 7.8 Global Outcomes: GO4 75) What type of reaction is: CH4 + 2O2 → CO2 + 2H2O + 218 kcal? A) an endothermic reaction B) an exothermic reaction C) a single replacement reaction D) a combination reaction E) a decomposition reaction Answer: B Objective: 7.9 Global Outcomes: GO2 76) How many kcal are produced when 32.0 g of CH4 react? CH4 + 2O2 → CO2 + 2H2O + 218 kcal A) 218 kcal B) 109 kcal C) 436 kcal D) 6.81 kcal E) 698 kcal Answer: C Objective: 7.9 Global Outcomes: GO4 77) For the reaction: 2H2O(l) + 137 kcal → 2H2 (g) + O2 (g), how many kcal are needed to form 2.00 moles O2 (g)? A) 68.5 kcal B) 137 kcal C) 274 kcal 22 Copyright © 2016 Pearson Education, Inc D) 190 kcal E) 548 kcal Answer: C Objective: 7.9 Global Outcomes: GO4 78) For the reaction: 2H2O(l) + 137 kcal → 2H2 (g) + O2 (g), how many kcal are needed to react 50.0 g H2O(l)? A) 380 kcal B) 137 kcal C) 274 kcal D) 190 kcal E) 760 kcal Answer: D Objective: 7.9 Global Outcomes: GO4 79) If the reaction shown below is exothermic, the energy level of the reactants is H2 + O2 → 2H2O A) lower than that of the products B) higher than that of the products C) the same as that of the products D) possibly lower, possibly higher than that of the products E) higher than the activation energy of the reaction Answer: B Objective: 7.9 Global Outcomes: GO2 80) In an endothermic reaction A) heat flows out of the system B) energy is absorbed by the system C) the temperature of the system increases D) the products have less energy that the reactants E) the products have the same energy that the reactants Answer: B Objective: 7.9 Global Outcomes: GO2 23 Copyright © 2016 Pearson Education, Inc 81) Any reaction that absorbs 150 kcal of energy can be classified as A) endothermic B) exothermic C) activated D) reduction E) oxidation Answer: A Objective: 7.9 Global Outcomes: GO2 82) The is the energy difference between reactants and products in a chemical reaction A) transition energy B) activation energy C) product energy D) overall energy E) heat of reaction Answer: E Objective: 7.9 Global Outcomes: GO2 83) The is the minimum energy needed for a chemical reaction to begin A) reaction energy B) activation energy C) energy of reactants D) energy of products E) heat of reaction Answer: B Objective: 7.9 Global Outcomes: GO2 84) A reaction that releases energy as it occurs is classified as a(n) A) endothermic reaction B) exothermic reaction C) oxidation-reduction reaction D) catalyzed reaction E) decomposition reaction Answer: B Objective: 7.9 Global Outcomes: GO2 24 Copyright © 2016 Pearson Education, Inc 7.2 Bimodal Questions 1) In this reaction, what is the correct coefficient for hydrogen gas? ? H2 + ? O2 → ? H2O A) B) C) D) E) Answer: B Objective: 7.1 Global Outcomes: GO4 Barium chloride and sodium sulfate react according to the following equation BaCl2 + Na2SO4 → BaSO4 + 2NaCl Answer the question(s) that follow about this reaction 2) How many moles of barium sulfate are produced from 0.100 mole of barium chloride? A) 0.0100 mole B) 0.100 mole C) 0.200 mole D) 1.00 mole E) 2.00 moles Answer: B Objective: 7.6 Global Outcomes: GO4 3) How many grams of barium sulfate can be produced from 20.8 g of barium chloride? A) 1.37 g B) 2.33 g C) 23.3 g D) 137 g E) 233 g Answer: C Objective: 7.7 Global Outcomes: GO4 25 Copyright © 2016 Pearson Education, Inc 4) How many grams of barium chloride are needed to make 100 grams of barium sulfate? A) 44.9 g B) 89.2 g C) 208.3 g D) 233.3 g E) 46.6 g Answer: B Objective: 7.7 Global Outcomes: GO4 Answer the question(s) that follow about the following reaction 2H2O2 → 2H2O + O2 5) How many moles of oxygen gas can 0.88 mole of hydrogen peroxide (H 2O2) produce, if decomposition is complete? A) 0.50 mole B) 0.88 mole C) 1.8 moles D) 2.0 moles E) 0.44 mole Answer: E Objective: 7.6 Global Outcomes: GO4 6) How many grams of water will 100 grams of hydrogen peroxide (H 2O2) produce? A) 3600 g B) 360 g C) 5.88 g D) 52.9 g E) 106 g Answer: D Objective: 7.7 Global Outcomes: GO4 7) How many grams of hydrogen peroxide (H2O2) are needed to produce 25.0 g of oxygen? A) 106 g B) 26.6 g C) 5.88 g D) 25.0 g E) 53.1 g Answer: E Objective: 7.7 Global Outcomes: GO4 26 Copyright © 2016 Pearson Education, Inc 8) How many moles of hydrogen peroxide (H2O2) are needed to produce 5.0 moles of water? A) 1.0 mole B) 2.0 moles C) 4.0 moles D) 5.0 moles E) 8.0 moles Answer: D Objective: 7.6 Global Outcomes: GO4 7.3 Short Answer Questions 1) What type of reaction is the following? 2KClO3 → 2KCl + 3O2 Answer: decomposition reaction Objective: 7.2 Global Outcomes: GO2 2) What type of reaction is the following? Zn + 2HCl → ZnCl2 + H2 Answer: single replacement reaction Objective: 7.2 Global Outcomes: GO2 3) What type of reaction is the following? 2KClO3 → 2KCl + 3O2 Answer: decomposition reaction Objective: 7.2 Global Outcomes: GO2 4) What type of reaction is the following? Zn + 2HCl → ZnCl2 + H2 Answer: single replacement reaction Objective: 7.2 Global Outcomes: GO2 5) The number of particles in mole of hydrogen gas is Answer: 6.02 × 1023 Objective: 7.4 Global Outcomes: GO4 27 Copyright © 2016 Pearson Education, Inc 6) The molar mass of copper(II) nitrate, Cu(NO3)2 is Answer: 187.6 g Objective: 7.5 Global Outcomes: GO4 7) What is the mass of mole of argon gas? Answer: 40.0 g Objective: 7.5 Global Outcomes: GO4 8) What is the mass of mole of helium gas? Answer: 4.00 g Objective: 7.5 Global Outcomes: GO4 9) Acetylene gas, C2H2, reacts with oxygen according to the following equation If 1.00 mole of acetylene reacts completely with sufficient oxygen, how many moles of carbon dioxide are produced? 2C2H2 + 5O2 → 4CO2 + 2H2O Answer: 2.00 moles of CO2 Objective: 7.6 Global Outcomes: GO4 7.4 True/False Questions 1) The following reaction is balanced KClO3 → KCl + O2 Answer: FALSE Objective: 7.1 Global Outcomes: GO2 2) The following is a decomposition reaction 2KClO3 → 2KCl + 3O2 Answer: TRUE Objective: 7.2 Global Outcomes: GO2 3) Loss of electrons is an oxidation Answer: TRUE Objective: 7.3 Global Outcomes: GO2 4) Avogadro's number is the number of grams in a mole Answer: FALSE Objective: 7.4 Global Outcomes: GO4 5) The molar mass of silver is 47 g Answer: FALSE Objective: 7.5 Global Outcomes: GO4 6) The molar mass of magnesium is 24.3 g Answer: TRUE 28 Copyright © 2016 Pearson Education, Inc Objective: 7.5 Global Outcomes: GO4 7) The mass of one mole of water is 18.0 g Answer: TRUE Objective: 7.5 Global Outcomes: GO4 8) The molar mass of chlorine gas is 35.5 g Answer: FALSE Objective: 7.5 Global Outcomes: GO4 9) The molar mass of copper(II) chloride is 134.5 g Answer: TRUE Objective: 7.5 Global Outcomes: GO4 10) In the reaction of hydrogen gas with oxygen gas to produce water, mole of oxygen gas can produce moles of water, given sufficient hydrogen available Answer: TRUE Objective: 7.6 Global Outcomes: GO4 11) In the reaction of hydrogen gas with oxygen gas to produce water, 16.0 g of oxygen gas can produce 9.00 g of water, given sufficient hydrogen available 2H2 + O2 → 2H2O Answer: FALSE Objective: 7.7 Global Outcomes: GO4 12) The % yield is the ratio of the theoretical yield to the actual yield multiplied by 100 Answer: FALSE Objective: 7.9 Global Outcomes: GO2 13) In an exothermic reaction, heat is a product Answer: TRUE Objective: 7.9 Global Outcomes: GO1 29 Copyright © 2016 Pearson Education, Inc 7.5 Matching Questions Identify the energy associated with each of the labeled parts of the following diagram A) energy of reactants B) heat of reaction C) activation energy D) energy of products 1) Region A Objective: 7.9 Global Outcomes: GO3 2) Region B Objective: 7.9 Global Outcomes: GO3 3) Region C Objective: 7.9 Global Outcomes: GO3 4) Region D Objective: 7.9 Global Outcomes: GO3 Answers: 1) A 2) C 3) B 4) D 30 Copyright © 2016 Pearson Education, Inc Identify the letter of the diagram corresponding to the given type of reaction A B A) Diagram A B) Diagram B 5) endothermic reaction Objective: 7.9 Global Outcomes: GO3 6) exothermic reaction Objective: 7.9 Global Outcomes: GO3 Answers: 5) B 6) A 31 Copyright © 2016 Pearson Education, Inc ... g E) 0 .70 0 g Answer: D Objective: 7. 5 Global Outcomes: GO4 36) Calculate the molar mass of potassium chloride, KCl A) 74 .6 g B) 54.5 g C) 6 .74 g D) 67. 4 g E) 19.0 g Answer: A Objective: 7. 5 Global... C Objective: 7. 9 Global Outcomes: GO4 77 ) For the reaction: 2H2O(l) + 1 37 kcal → 2H2 (g) + O2 (g), how many kcal are needed to form 2.00 moles O2 (g)? A) 68.5 kcal B) 1 37 kcal C) 274 kcal 22 Copyright... Objective: 7. 9 Global Outcomes: GO4 78 ) For the reaction: 2H2O(l) + 1 37 kcal → 2H2 (g) + O2 (g), how many kcal are needed to react 50.0 g H2O(l)? A) 380 kcal B) 1 37 kcal C) 274 kcal D) 190 kcal E) 76 0