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Bonus Final Exam 3—————————————————————————————————————

1 Calculate the heat of reaction,ΔHrxn0 , for the following reaction as written at 298 K:

CH4g 2F2g → CF4g 2H2g

substance CH4g CF4gΔHf0 kJ/mol −75 −680

(A) ΔHrxn0 203 kJ(B) ΔHrxn0 −914 kJ(C) ΔHrxn0 −755 kJ(D) ΔHrxn0 −605 kJ(E) ΔHrxn0 302 kJ

2 Consider the combustion of propane:C3H8g 5O2g → 3CO2g 4H2Ol ΔH0 −2220 kJ

How much heat is liberated when 10.0 g of C3H8g is burned to produce products at 1atm pressure?(A) 23.1 kJ(B) 503 kJ(C) 2.22104 kJ(D) 2.22 103 kJ(E) 13.9 kJ

3 What is the PH when 50 mL of 0.10 M HC2H3O2 is titrated with 50mL of 0.10 M NaOH?The Ka of HC2H3O2 is 1.8 10−5.(A) PH 9.26(B) PH 2.60(C) PH 4.74(D) PH 1.48(E) PH 8.72

4 Consider the calculated value of KP for the following equilibrium at 249∘C:

2NOg Cl2g 2NOClg; KP 30.9

Which of the choices is TRUE for the gas mixture with the partial pressuresP NO 8.13 atm, P Cl2 1.36 atm, and P NOCl 6.99atm?(A) Q KP and some product will be converted to reactants in order to achieveequilibrium.(B) Q KP and some reactants will be converted to product in order to achieveequilibrium.(C) Q KP and some product will be converted to reactants in order to achieveequilibrium.(D) Q KP and the reaction mixture is at equilibrium.(E) Q KP and some reactants will be converted to product in order to achieveequilibrium.

5 Based on the Ka values given which of the acids listed below is the STRONGEST acid?(A) propionic acid Ka 1.3 10−5(B) benzoic acid Ka 6.3 10−5(C) butanoic acid Ka 1.5 10−5(D) hydrofluoric acid Ka 6.8 10−4(E) lactic acid Ka 1.4 10−4

6 The decomposition of CH3N2CH3, shown below, is a first-order reaction with a half lifeof 32.1 min at 327∘C. Initially the concentration of CH3N2CH3 is 8.9210−2M. What isthe concentration after 26.1 min?

CH3N2CH3g → C2H6g N2g

(A) 5.0810−2M(B) 8.4610−3M(C) 7.2510−2M(D) 1.5710−1M(E) 1.2110−2M

7 ΔHrxn0 −802.3 kJ for the following reaction, as written, at 298 K:

CH4g 2O2g → CO2g 2H2Ol

Which of the following statements is TRUE?(A) At constant volume, w -802.3 kJ.(B) q - w(C) At constant volume, q -802.3 kJ.(D) Heat flows into the surroundings.(E) When 2 mol of H2Ol is produced ΔHrxn0 802.3 kJ.

8 Which of the following compounds, when added to water, will make an acidic solution?NaCl NaF NaC2H3O2 NH4Cl

(A) Only NaC2H3O2 will make an acidic solution.(B) NaCl and NaF will make acidic solutions.(C) NH3 and NaC2H3O2 will make acidic solutions.(D) NaC2H3O2 and NH4Cl will make acidic solutions.(E) Only NH4Cl will make an acidic solutions.

9 Choose the selection which lists the following acids in order of INCREASING acidstrength (weakest acid first).

HClO2 HClO3 HClO4 HIO2 HBrO2(A) HClO2 HClO3 HClO4 HBrO2 HIO2(B) HClO4 HClO3 HClO2 HBrO2 HIO2(C) HClO2 HClO3 HClO4 HIO2 HBrO2(D) HClO2 HBrO2 HIO2 HClO3 HClO4(E) HIO2 HBrO2 HClO2 HClO3 HClO4

10 Consider the following equilibrium for which ΔHrxn0 180.74 kJN2g O2g 2NOg

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 0.235 M HIO4 are needed to titrate 64.5 mL of 0.212 M NaOH tothe 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:N2g 2O2g → 2NO2g ΔHrxn0 66.4 kJ

2NOg O2g → 2NO2g ΔHrxn0 −114.2 kJ

Calculate the standard enthalpy of reaction for the reaction: N2g O2g →2NOg.(A) ΔHrxn0 −47.8 kJ(B) ΔHrxn0 47.8 kJ(C) ΔHrxn0 −180.6 kJ(D) ΔHrxn0 180.6 kJ(E) ΔHrxn0 90.3 kJ

13 Arrange the following species in order of DECREASING OXIDIZING strength(strongest oxidizing agent first):

F2g O2g Fe2aq MnO4−aq H

aq

(A) O2 MnO4− F2 H Fe2

(B) F2 MnO4− O2 H Fe2

(C) F2 O2 Fe2 MnO4− H

(D) H Fe2 Fe2 O2 MnO4−

(E) MnO4− O2 F2 H Fe2

14 When a hot lava rock is dropped into 100 g of water at 25.0∘C the rock releases 4.97 kJ ofheat to the water. What is the final temperature of the water?The specific heat of water is 4.18 J/(g0 C).(A) 27.4∘C(B) 59.0∘C(C) 36.9∘C

(D) 11.9∘C(E) 29.8∘C

15 Consider the following reaction: 2NOg 2H2g →N2g 2H2Og.Use the following data to determine the rate law for this reaction.

Exp NO0

H2 0Initial Rate M/s

1 0.0126 0.0125 0.242 0.0252 0.0250 1.903 0.0252 0.0125 0.96

(A) Rate k NO 2 H22

(B) Rate k NO 1/2 H2(C) Rate k NO 2 H2(D) Rate k NO H2

2

(E) Rate k NO H2

16 A mixture consisting of 100g of solid sodium hydroxide, 100g of solid sodium hydrogencarbonate, and 2.5 atm of carbon dioxide is placedinto a sealed 1.00-L steel reaction vessel. This mixture is heated to 700 K and allowed tocome to equilibrium according to the followingreaction:

NaOHs CO2g NaHCO3s; Kp 2.5

What is the equilibrium partial pressure of carbon dioxide?(A) 3.010−1 atm(B) 1.910−1 atm(C) 4.010−1 atm(D) 3.7 atm(E) 2.5 atm

17 The overall cell reaction for the ELECTROLYSIS shown below is:Cd2aq Cus →Cdg Cu2aqWhich of the following statements is FALSE?(A) The mass of the Cds electrode will increase during the electrolysis.(B) The mass of the Cus 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 1.0 M Cu2 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 courseof the reaction?2KMnO4aq 10KIaq 16HClaq →2MnCl2aq 5I2s 12KClaq 10H2Ol(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 thevalue of ΔGrxn0 for the reaction shown below.

2MnO4−aq 10I−aq 16H

aq → 2Mn2aq 5I2s 8H2Ol

(A) ΔGrxn0 −93.6 kJ(B) ΔGrxn0 936 kJ(C) ΔGrxn0 1978 kJ(D) ΔGrxn0 −1978 kJ(E) ΔGrxn0 −936 kJ

20 Calculate the PH of a solution prepared by dissolving 0.37 mol of hypochlorous acidHClO and 0.23 mol of sodium hypochlorite NaOClin water with a total volume of 1.00 L of solution.The Ka of hypochlorous acid is 3.010−8.(A) PH 6.48(B) PH 4.19(C) PH 8.38(D) PH 7.32(E) PH 7.73

21 Calculate ΔGrxn0 for the reaction shown below at 1000 K given the following data.

(Assume that ΔHrxn0 and ΔSrxn0 do not depend on temperature.)2NO2g → N2O4g

NO2g N2O4gΔHf0 kJ/mol 33.9 9.66

S0 J/mol K 240.5 304.3

Which of the following statements is CORRECT if all gases are present at 1 atm ofpressure?(A) ΔGrxn0 118.6 kJ; this reaction favors reactants.(B) ΔGrxn0 −1.77 105; this reaction favors reactants.(C) ΔGrxn0 0; this reaction is at equilibrium.(D) ΔGrxn0 −118.6 kJ; this reaction favors products.(E) ΔGrxn0 1.77 105 kJ; this reaction favors products.

22 Using the energy diagram below calculate the activation energy for the REVERSEreaction.

(A) Earev 54 kJ/mol(B) Earev 24 kJ/mol(C) Earev 30 kJ/mol(D) Earev 74 kJ/mol(E) Earev 94 kJ/mol

23 A layer of chromium is electroplated onto an automobile bumper by passing a constantcurrent of 200.0 A through a cell that contains Cr NO3 3

aq.How many minutes arerequired to deposit 125g of chromium?

(A) 129 min(B) 3480 min(C) 6.44 min(D) 58.0 min(E) 19.3 min

24 For a process to be spontaneous itMUST 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 Suniv 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 Kp 1.49 108 at 373 K

COg Cl2g COCl2g

In an equilibrium mixture of the three gages, PCOPCl2 8.60 10−4atm. The partialpressure of the product COCl2 is atm.(A) 4.96 10−15 atm(B) 1.10 102 atm(C) 2.01 1014 atm(D) 1.72 1011 atm(E) 1.28 105 atm

26 Calculate the PH of a 2.16 M solution of NaF.The Ka for HF is 6.8 10−4.(A) PH 2.16(B) PH 5.24(C) PH 10.83(D) PH 8.75(E) PH 0.33

27 Calculate the OH−aqconcentration of a solution with a PH of 9.30.(A) OH− 5.0 10−10M

(B) OH− 5.0 104M(C) OH− 6.7 10−1M(D) OH− 2.0 10−5M(E) OH− 9.3 10−1M

28 What is the PH of a solution made by dissolving 15.1 g of acetic acid, HC2H3O2, inenough water to make 100 mL of solution? The Ka of HC2H3O2 is 1.8 10−5.(A) PH 0.61(B) PH 2.17(C) PH 4.72(D) PH 2.71(E) PH 3.70

29 Balance the following redox reaction in ACIDIC solution with the smallest possiblewhole-number coefficients:

ClO4−aq Mn2aq → Cl2g MnO2s

What is the coefficient in front of Haq when this reaction is balanced?(A) 2(B) 4(C) 6(D) 8(E) 12

30 Kp 6.64 10−58 for the following reaction:3O2g 2O3g

Which of the following are TRUE?(i) At equilibrium, P O2 P O3 .(ii) At equilibrium, P O2 P O3 .(iii) At equilibrium, DECREASING the volume will shift the equilibrium towardREACTANT.(iv) At equilibrium, INCREASING the volume will shift the equilibrium towardREACTANT.(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:4NH3g O2g → 2N2H4g 2H2Og

At 298 K, ΔHrxn0 −108.08 kJ and ΔSrxn0 −120.34 J/K. Calculate the value of KP forthis reaction at 436 K. Assume that ΔHrxn0 and ΔSrxn0 do not depend on temperature.(A) KP 1.02(B) KP 2.17 10−7(C) KP 4.60 106(D) KP 5.33 10−7(E) KP 4.56 1012

32 Consider the combustion of propylene:2C3H6g 9O2g → 6CO2g 6H2Og

If oxygen is consumed at the rate of 0.11 M/s by this reaction, what is the rate ofproduction of carbon dioxide?(A) 5.9 M/s.(B) 0.66 M/s.(C) 0.073 M/s.(D) 0.038 M/s.(E) 0.17 M/s.

33 Calculate the concentration of iodide ions in a saturated solution of lead II iodide. Thesolubility product constant of PbI2 is Ksp 1.4 10−8.(A) 3.8 10−4M(B) 1.5 10−3M(C) 3.5 10−9M(D) 3.0 10−3M(E) 1.4 10−8M

34 Which of the following statements about collision theory in kinetics is FALSE for thefollowing elementary reaction?

Ag Bg → Productsg

(A) High temperatures do not speed up reaction rates.(B) Not every collision results in reaction.(C) Molecules with E much less than Ea 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 changefor the process shown below?

Nas → Nal(A) ΔH0 0 and ΔS0 0(B) ΔH0 0 and ΔS0 0(C) ΔH0 0 and ΔS0 0(D) ΔH0 0 and ΔS0 0(E) ΔH0 0 and ΔS0 0