Bonus Final Exam 3 1 Calculate the heat of reaction,δh rxn, for the following reaction as written at 298 K: CH 4 2F 2 CF 4 2H 2 substance CH 4 CF 4 ΔH f kj/mol 75 68 (A) ΔH rxn 23 kj (B) ΔH rxn 914 kj (C) ΔH rxn 755 kj (D) ΔH rxn 65 kj (E) ΔH rxn 32 kj 2 Consider the combustion of propane: C 3 H 8 5O 2 3CO 2 4H 2 O l ΔH 222 kj How much heat is liberated when 1. g of C 3 H 8 is burned to produce products at 1 atm pressure? (A) 23.1 kj (B) 53 kj (C) 2.22 1 4 kj (D) 2.22 1 3 kj (E) 13.9 kj 3 What is the P H when 5 ml of.1 M HC 2 H 3 O 2 is titrated with 5mL of.1 M NaOH? The K a of HC 2 H 3 O 2 is 1.8 1 5. (A) P H 9.26 (B) P H 2.6 (C) P H 4.74 (D) P H 1.48 (E) P H 8.72
4 Consider the calculated value of K P for the following equilibrium at 249 C: 2NO Cl 2 2NOCl; K P 3.9 Which of the choices is TRUE for the gas mixture with the partial pressures P NO 8.13 atm, P Cl 2 1.36 atm, and P NOCl 6.99 atm? (A) Q K P and some product will be converted to reactants in order to achieve equilibrium. (B) Q K P and some reactants will be converted to product in order to achieve equilibrium. (C) Q K P and some product will be converted to reactants in order to achieve equilibrium. (D) Q K P and the reaction mixture is at equilibrium. (E) Q K P and some reactants will be converted to product in order to achieve equilibrium. 5 BasedontheK a values given which of the acids listed below is the STRONGEST acid? (A) propionic acid K a 1.3 1 5 (B) benzoic acid K a 6.3 1 5 (C) butanoic acid K a 1.5 1 5 (D) hydrofluoric acid K a 6.8 1 4 (E) lactic acid K a 1.4 1 4 6 The decomposition of CH 3 N 2 CH 3, shown below, is a first-order reaction with a half life of 32.1 min at 327 C. Initially the concentration of CH 3 N 2 CH 3 is 8.92 1 2 M. What is the concentration after 26.1 min? (A) 5.8 1 2 M (B) 8.46 1 3 M (C) 7.25 1 2 M (D) 1.57 1 1 M (E) 1.21 1 2 M CH 3 N 2 CH 3 C 2 H 6 N 2 7 ΔH rxn 82.3 kj for the following reaction, as written, at 298 K:
CH 4 2O 2 CO 2 2H 2 O l Which of the following statements is TRUE? (A) At constant volume, w -82.3 kj. (B) q -w (C) At constant volume, q -82.3 kj. (D) Heat flows into the surroundings. (E) When 2 mol of H 2 O l is produced ΔH rxn 82.3 kj. 8 Which of the following compounds, when added to water, will make an acidic solution? NaCl NaF NaC 2 H 3 O 2 NH 4 Cl (A) OnlyNaC 2 H 3 O 2 will make an acidic solution. (B) NaCl and NaF will make acidic solutions. (C) NH 3 and NaC 2 H 3 O 2 will make acidic solutions. (D) NaC 2 H 3 O 2 and NH 4 Cl will make acidic solutions. (E) Only NH 4 Cl will make an acidic solutions. 9 Choose the selection which lists the following acids in order of INCREASING acid strength (weakest acid first). HClO 2 HClO 3 HClO 4 HIO 2 HBrO 2 (A) HClO 2 HClO 3 HClO 4 HBrO 2 HIO 2 (B) HClO 4 HClO 3 HClO 2 HBrO 2 HIO 2 (C) HClO 2 HClO 3 HClO 4 HIO 2 HBrO 2 (D) HClO 2 HBrO 2 HIO 2 HClO 3 HClO 4 (E) HIO 2 HBrO 2 HClO 2 HClO 3 HClO 4 1 Consider the following equilibrium for which ΔH rxn 18.74 kj N 2 O 2 2NO Which of the following shifts the equilibrium toward products? (A) adding a catalyst (B) decreasing volume (C) raising the temperature (D) adding nitrogen monoxide (E) removing nitrogen
11 How many milliliters of.235 M HIO 4 are needed to titrate 64.5 ml of.212 M NaOH to the equivalence point? (A) 58.2 ml (B) 17.2 ml (C) 71.5 ml (D) 3.2 ml (E) 1.3 ml 12 Give the following reactions: N 2 2O 2 2NO 2 2NO O 2 2NO 2 ΔH rxn 66.4 kj ΔH rxn 114.2 kj Calculate the standard enthalpy of reaction for the reaction: N 2 O 2 2NO. (A) ΔH rxn 47.8 kj (B) ΔH rxn 47.8 kj (C) ΔH rxn 18.6 kj (D) ΔH rxn 18.6 kj (E) ΔH rxn 9.3 kj 13 Arrange the following species in order of DECREASING OXIDIZING strength (strongest oxidizing agent first): F 2 O 2 Fe 2 aq MnO 4 aq H aq (A) O 2 MnO 4 F 2 H Fe 2 (B) F 2 MnO 4 O 2 H Fe 2 (C) F 2 O 2 Fe 2 MnO 4 H (D) H Fe 2 Fe 2 O 2 MnO 4 (E) MnO 4 O 2 F 2 H Fe 2 14 When a hot lava rock is dropped into 1 g of water at 25. C the rock releases 4.97 kj of heat to the water. What is the final temperature of the water? The specific heat of water is 4.18 J/(g C). (A) 27.4 C (B) 59. C (C) 36.9 C
(D) 11.9 C (E) 29.8 C 15 Consider the following reaction: 2NO 2H 2 N 2 2H 2 O. Use the following data to determine the rate law for this reaction. (A) Rate k NO 2 H 2 2 (B) Rate k NO 1/2 H 2 (C) Rate k NO 2 H 2 (D) Rate k NO H 2 2 (E) Rate k NO H 2 Exp NO H 2 Initial Rate M/s 1.126.125.24 2.252.25 1.9 3.252.125.96 16 A mixture consisting of 1g of solid sodium hydroxide, 1g of solid sodium hydrogen carbonate, and 2.5 atm of carbon dioxide is placed into a sealed 1.-L steel reaction vessel. This mixture is heated to 7 K and allowed to come to equilibrium according to the following reaction: NaOH s CO 2 NaHCO 3 s ; K p 2.5 What is the equilibrium partial pressure of carbon dioxide? (A) 3. 1 1 atm (B) 1.9 1 1 atm (C) 4. 1 1 atm (D) 3.7 atm (E) 2.5 atm 17 The overall cell reaction for the ELECTROLYSIS shown below is: Cd 2 aq Cu s Cd Cu 2 aq Which of the following statements is FALSE? (A) The mass of the Cd s electrode will increase during the electrolysis. (B) The mass of the Cu s electrode will decrease during the electrolysis.
(C) The copper electrode is the anode and the cadmium electrode is the cathode. (D) Cations migrate from the salt bridge into the 1. M Cu 2 solution. (E) Electrons flow from the copper electrode to the cadmium electrode. 18 Consider the redox reaction shown below. Which element is REDUCED during the course of the reaction? 2KMnO 4 aq 1KI aq 16HCl aq 2MnCl 2 aq 5I 2 s 12KCl aq 1H 2 O l (A) Mn (B) O (C) I (D) Cl (E) H 19 Using data in the standard reduction potentials table at the front of this exam calculate the value of ΔG rxn for the reaction shown below. 2MnO 4 aq 1I aq 16H aq 2Mn 2 aq 5I 2 s 8H 2 O l (A) ΔG rxn 93.6 kj (B) ΔG rxn 936 kj (C) ΔG rxn 1978 kj (D) ΔG rxn 1978 kj (E) ΔG rxn 936 kj 2 Calculate the P H of a solution prepared by dissolving.37 mol of hypochlorous acid HClO and.23 mol of sodium hypochlorite NaOCl in water with a total volume of 1. L of solution. The K a of hypochlorous acid is 3. 1 8. (A) P H 6.48 (B) P H 4.19 (C) P H 8.38 (D) P H 7.32 (E) P H 7.73 21 Calculate ΔG rxn for the reaction shown below at 1 K given the following data.
(Assume that ΔH rxn and ΔS rxn do not depend on temperature.) 2NO 2 N 2 O 4 NO 2 N 2 O 4 ΔH f kj/mol 33.9 9.66 S J/mol K 24.5 34.3 Which of the following statements is CORRECT if all gases are present at 1 atm of pressure? (A) ΔG rxn 118.6 kj; this reaction favors reactants. (B) ΔG rxn 1.77 1 5 ;this reaction favors reactants. (C) ΔG rxn ; this reaction is at equilibrium. (D) ΔG rxn 118.6 kj; this reaction favors products. (E) ΔG rxn 1.77 1 5 kj; this reaction favors products. 22 Using the energy diagram below calculate the activation energy for the REVERSE reaction. (A) E a rev 54 kj/mol (B) E a rev 24 kj/mol (C) E a rev 3 kj/mol (D) E a rev 74 kj/mol (E) E a rev 94 kj/mol 23 A layer of chromium is electroplated onto an automobile bumper by passing a constant current of 2. A through a cell that contains Cr NO 3 aq.how many minutes are 3 required to deposit 125g of chromium?
(A) 129 min (B) 348 min (C) 6.44 min (D) 58. min (E) 19.3 min 24 For a process to be spontaneous it MUST be true that... (A) heat is transferred from the system to the surroundings. (B) both the enthalpy and the entropy of the system decrease. (C) the Gibbs free energy of the system decreases and S univ increases. (D) the entropy change of the system is zero. (E) the entropy change of the system is positive. 25 Consider the following equilibrium, for which K p 1.49 1 8 at 373 K CO Cl 2 COCl 2 In an equilibrium mixture of the three gages, P CO P Cl2 8.6 1 4 atm. The partial pressure of the product COCl 2 is atm. (A) 4.96 1 15 atm (B) 1.1 1 2 atm (C) 2.1 1 14 atm (D) 1.72 1 11 atm (E) 1.28 1 5 atm 26 Calculate the P H of a 2.16 M solution of NaF. The K a for HF is 6.8 1 4. (A) P H 2.16 (B) P H 5.24 (C) P H 1.83 (D) P H 8.75 (E) P H.33 27 Calculate the OH aq concentration of a solution with a P H of 9.3. (A) OH 5. 1 1 M
(B) OH 5. 1 4 M (C) OH 6.7 1 1 M (D) OH 2. 1 5 M (E) OH 9.3 1 1 M 28 What is the P H of a solution made by dissolving 15.1 g of acetic acid, HC 2 H 3 O 2,in enough water to make 1 ml of solution? The K a of HC 2 H 3 O 2 is 1.8 1 5. (A) P H.61 (B) P H 2.17 (C) P H 4.72 (D) P H 2.71 (E) P H 3.7 29 Balance the following redox reaction in ACIDIC solution with the smallest possible whole-number coefficients: ClO 4 aq Mn 2 aq Cl2 MnO 2 s What is the coefficient in front of H aq when this reaction is balanced? (A) 2 (B) 4 (C) 6 (D) 8 (E) 12 3 K p 6.64 1 58 for the following reaction: Which of the following are TRUE? (i) At equilibrium, P O 2 P O 3. (ii) At equilibrium, P O 2 P O 3. 3O 2 2O 3 (iii) At equilibrium, DECREASING the volume will shift the equilibrium toward REACTANT. (iv) At equilibrium, INCREASING the volume will shift the equilibrium toward REACTANT. (A) (ii) and (iv) are true. (B) (ii) and (iii) are true. (C) (i) and (iv) are true.
(D) Only (i) is true. (E) (i) and (iii) are true. 31 Consider the following reaction: 4NH 3 O 2 2N 2 H 4 2H 2 O At 298 K, ΔH rxn 18.8 kj and ΔS rxn 12.34 J/K. Calculate the value of K P for this reaction at 436 K. Assume that ΔH rxn and ΔS rxn do not depend on temperature. (A) K P 1.2 (B) K P 2.17 1 7 (C) K P 4.6 1 6 (D) K P 5.33 1 7 (E) K P 4.56 1 12 32 Consider the combustion of propylene: 2C 3 H 6 9O 2 6CO 2 6H 2 O If oxygen is consumed at the rate of.11 M/s by this reaction, what is the rate of production of carbon dioxide? (A) 5.9 M/s. (B).66 M/s. (C).73 M/s. (D).38 M/s. (E).17 M/s. 33 Calculate the concentration of iodide ions in a saturated solution of lead II iodide. The solubility product constant of PbI 2 is K sp 1.4 1 8. (A) 3.8 1 4 M (B) 1.5 1 3 M (C) 3.5 1 9 M (D) 3. 1 3 M (E) 1.4 1 8 M 34 Which of the following statements about collision theory in kinetics is FALSE for the following elementary reaction? A B Products
(A) High temperatures do not speed up reaction rates. (B) Not every collision results in reaction. (C) Molecules with E much less than E a have a low probability of reaction. (D) The orientation of the collision affects the probability of reaction. (E) The more frequently molecules collide with one another during a chemical reaction, the greater the reaction rate. 35 Which CORRECTLY indicates the signs of the enthalpy change and the entropy change for the process shown below? (A) ΔH and ΔS (B) ΔH and ΔS (C) ΔH and ΔS (D) ΔH and ΔS (E) ΔH and ΔS Na s Na l