Summer 2003 CHEMISTRY 115 FINAL (A) 1. The expression for the equilibrium constant depends on: A. reaction mechanism B. stoichiometry C.

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1 Summer 2003 CHEMISTRY 115 FINAL (A) 1. The expression for the equilibrium constant depends on: A. reaction mechanism B. stoichiometry C. activation barrier D. concentration of the catalyst 2. For the equilibrium CH 4 (g) 2O 2 (g) CO 2 (g) 2H 2 O(g) adding O 2 will affect the equilibrium in the following way: A. increase the value of the equilibrium constant B. increase the concentration of H 2 O (g) at equilibrium C. decrease the concentration of CO 2 (g) at equilibrium D. cause the reaction to shift to left 3. The normal boiling point of CCl 4 (l) is 350 K and its enthalpy of vaporization is H vap = 30.0 kj/mol. Calculate S when 1.00 mol of CCl 4 condenses at 350 K: A. 86 J/K B. 162 J/K C. 86 J/K D J/K 4. Equilibrium for a reaction corresponds to: A. minimum of the Gibbs energy G B. maximum concentration of the products C. equilibrium constant equal to zero D. reaction quotient equal to one 5. For a certain reaction at T= 300 K, H = 20. kj and S = J/K. This reaction is: A. exothermic and nonspontaneous B. exothermic and spontaneous C. endothermic and nonspontaneous D. endothermic at equilibrium 6. The value of K c for the equilibrium H 2 (g) I 2 (g) 2HI(g) is 794 at 25 o C. At this temperature, what is the value of K c for the reaction: (1/2)H 2 (g) (1/2)I 2 (g) HI(g)? A. 397 B C. 28 D The value of K c for the following reaction is What is the equilibrium concentration (M) of C 4 H 10 if the equilibrium concentrations of C 2 H 6 and C 2 H 4 are both M? C 4 H 10 (g) C 2 H 6 (g) C 2 H 4 (g) A B C. 57

2 D Which of the following processes causes a decrease in the system entropy? A. boiling water to form steam B. freezing water to make ice C. dissolution of solid KCl in water D. mixing of two gases in one container 9. Which of the following compounds will have zero standard free energy of formation? A. Co(s) B. H 2 O(l) C. O(g) D. PF 3 (g) 10. The rate constant for a particular reaction is 1.3 x 10 4 M 2 s 1 at 200 K. What is the overall order of the reaction? A. 2 B. 1 C. 3 D The reaction CH 3 N C CH 3 C N is a first order reaction with the rate constant k=6.29 x 10 4 s 1. Calculate the concentration of CH 3 C N after 1000 s if the initial concentration of CH 3 N C is M. A x 10 4 B x 10 4 C x 10 3 D x Using the sketch below calculate the activation energy of the reverse raction A. 40 kj/mol B. 20 kj/mol C. 60 kj/mol D. 80 kj/mol 13. The dependence of reaction rate on temperature for the reaction Cl NOCl NO Cl is measure at two values of pressure as is shown by lines 1 and 2 on the sketch below. At temperature T 0 the rate constant k 1 is greater than k 2 because: A. E a1 < E a2 B. Cl and NOCl collide more frequently for 1 C. Cl and NOCl collide more frequently for 2 D. the equilibrium is shifted to the right 14. The rate law for the reaction A B C is Rate = k[a] 2. What of the following will not increase the reaction rate? A. increase in temperature B. increase in the concentration of B C. increase in the concentration of A

3 D. adding a suitable catalyst 15. What is the conjugate acid of NH 3? A. NH 2 B. NH 3 C. NH 4 D. NH 4 OH 16. Using the table of relative strength of acidbase pairs identify the products of the reaction HSO 4 HS A. 2 SO 4 H 2 S B. H 2 SO 4 S 2 C. S 2 2 SO 4 D. 2 H 2 S SO What is the ph of 0.02 M solution of NaOH? A B C. 7.0 D The K a of HCN is 4.9 x What is the ph of 0.2 M solution of HCN? A B. 4.4 C. 5.0 D From the list below indicate the substance which will form a basic aqueous solution. A. NH 4 Cl B. KBr C. K 2 CO 3 D. Cu(NO 3 ) Consider the titration diagram shown on the plot below. What type of substance was originally in the flask? A. weak base B. weak acid C. strong base D. strong acid 21. In which of the following solutions would you expect AgBr to have the highest solubility? A M LiBr B. 0.1 M AgNO 3 C. pure water

4 D. 0.1 M NaBr 22. Calculate ph of a buffer composed of M HClO (K a = 3.0x10 8 ) and 0.1 M KClO. A B. 4.4 C. 2.6 D What is the molar solubility of Zn(OH) 2 (K sp = 3.0x10 16 )? A. 4.2 x 10 6 B. 2.1 x 10 3 C. 5.2 x 10 4 D. 6.7 x What is the oxidation number of Cr in K 2 CrO 4? A. 2 B. 4 C. 6 D Which element is oxidized in the reaction Fe 2 S 3 12HNO 3 2Fe(NO 3 ) 3 3S 6NO 2 6H 2 O A. S B. N C. Fe D. H 26. The balanced halfreaction in which the sulfate ion (SO 2 4 ) is reduced to sulfite ion (SO 2 3 ) is: A. a oneelectron processes B. a twoelectron processes C. a threeelectron processes D. a fourelectron processes 27. Respective standard reduction potentials of Sn 2 and Co 2 are V and V, respectively. An electrochemical cell is built from Co electrode in Co 2 solution and Sn electrode in Sn 2 solution. The reduction reaction will occur on the electrode which is called: A. Sn, anode B. Sn, cathode C. Co, anode D. Co, cathode 28. Using the table of standard reduction potentials indicate the metal which could provide cathode protection to Al: A. Cu B. Ag C. Zn D. Na 29. Calculate G 0 (in J) for the reaction Zn Cu 2 Zn 2 Cu (Zn 2 /Zn E 0 red = V; Cu 2 /Cu E o red = V) A. 106 kj

5 B. 340 kj C. 212 kj D. 424 kj 30. Which of the following processes results in an increase in the number of protons in the nucleus? A. gamma emission B. positron emission C. beta emission D. alpha emission 31. Balance the nuclear reaction to identify the identity of the element E: U α E. A. Pu B. Np C. Th D. Pa Pb has a halflife of 22.3 years and decay to produce 206 Hg. If you start with 7.50 g of 210 Pb, how many grams of 206 Hg will you have after 17.5 years? A B C D What of the following condition favors nuclear stability: A. neutrontoproton ration less than 1:2 B. atomic number > 92 C. even numbers of protons and neutrons D. chemical inertness 34. Which complex below has 2 unpaired electrons? A. squareplanar [Ni(CN) 4 ] 2 B. octahedral [Ni(NH 3 ) 6 ] 2 C. tetrahedral [CoCl 4 ] 2 D. lowspin octahedral [Fe(CN) 6 ] Based on the spectrochemical series F <NH 3 <NO 2 < CN, which of the complexes below is most likely highspin? A. [CrF 6 ] 3 B. [Co(NH 3 ) 6 ] 3 C. [Co(NO 2 ) 6 ] 3 D. [Co(CN) 6 ] What is the coordination number of [Co(en)F 4 ]? A. 4 B. 5 C. 6 D The most common isotope of hydrogen is: A. helium B. deuterium C. tritium

6 D. protium 38. Br 2 can be prepared by combining NaBr with A. HBr B. Cl 2 C. I 2 D. NaCl 39. Which oxide will produce a basic aqueous solution? A. CaO B. SO 3 C. NO 2 D. H 2 O 40. The oxidation state of oxygen in O 2 F 2 is: A. 0 B. 1 C. 1 D. 2 CHEMISTRY 115 FINAL (B) 1. The expression for the equilibrium constant depends on: A. stoichiometry B. reaction mechanism C. concentration of the catalyst D. activation barrier 2. For the equilibrium CH 4 (g) 2O 2 (g) CO 2 (g) 2H 2 O(g) adding O 2 will affect the equilibrium in the following way: a. increase the concentration of H 2 O (g) at equilibrium b. increase the value of the equilibrium constant c. cause the reaction to shift to left d. decrease the concentration of CO 2 (g) at equilibrium 3. The normal boiling point of CCl 4 (l) is 350 K and its enthalpy of vaporization is H vap = 30.0 kj/mol. Calculate S when 1.00 mol of CCl 4 condenses at 350 K: a J/K b. 86 J/K c. 162 J/K d. 86 J/K 4. Equilibrium for a reaction corresponds to: a. maximum concentration of the products b. reaction quotient equal to one c. equilibrium constant equal to zero d. minimum of the Gibbs energy G 5. For a certain reaction at T= 300 K, H = 20. kj and S = J/K. This reaction is: a. endothermic at equilibrium

7 b. endothermic and nonspontaneous c. exothermic and spontaneous d. exothermic and nonspontaneous 6. The value of K c for the equilibrium H 2 (g) I 2 (g) 2HI(g) is 794 at 25 o C. At this temperature, what is the value of K c for the reaction: (1/2)H 2 (g) (1/2)I 2 (g) HI(g)? a b. 28 c. 397 d The value of K c for the following reaction is What is the equilibrium concentration (M) of C 4 H 10 if the equilibrium concentrations of C 2 H 6 and C 2 H 4 are both M? C 4 H 10 (g) C 2 H 6 (g) C 2 H 4 (g) a b c d Which of the following processes causes a decrease in the system entropy? a. freezing water to make ice b. boiling water to form steam c. mixing of two gases in one container d. dissolution of solid KCl in water 9. Which of the following compounds will have zero standard free energy of formation? a. O(g) b. H 2 O(l) c. Co(s) d. PF 3 (g) 10. The rate constant for a particular reaction is 1.3 x 10 4 M 2 s 1 at 200 K. What is the overall order of the reaction? a. 4 b. 3 c. 1 d The reaction CH 3 N C CH 3 C N is a first order reaction with the rate constant k=6.29 x 10 4 s 1. Calculate the concentration of CH 3 C N after 1000 s if the initial concentration of CH 3 N C is M. a x 10 6 b x 10 3 c x 10 4 d x Using the sketch below calculate the activation energy of the reverse raction a. 60 kj/mol b. 20 kj/mol c. 40 kj/mol

8 d. 80 kj/mol 13. The dependence of reaction rate on temperature for the reaction Cl NOCl NO Cl is measure at two values of pressure as is shown by lines 1 and 2 on the sketch below. At temperature T 0 the rate constant k 1 is greater than k 2 because: a. Cl and NOCl collide more frequently for 1 b. E a1 < E a2 c. the equilibrium is shifted to the right d. Cl and NOCl collide more frequently for The rate law for the reaction A B C is Rate = k[a] 2. What of the following will not increase the reaction rate? a. increase in temperature b. increase in the concentration of B c. adding a suitable catalyst d. increase in the concentration of A 15. What is the conjugate acid of NH 3? a. NH 4 b. NH 2 c. NH 3 d. NH 4 OH 16. Using the table of relative strength of acidbase pairs identify the products of the reaction HSO 4 HS 2 E. H 2 S SO 4 F. H 2 SO 4 S 2 G. S 2 2 SO 4 2 H. SO 4 H 2 S 17. What is the ph of 0.02 M solution of NaOH? a b. 7.0 c d The K a of HCN is 4.9 x What is the ph of 0.2 M solution of HCN? a. 5.0 b. 2.3 c d. 4.4

9 19. From the list below indicate the substance which will form a basic aqueous solution. a. KBr b. NH 4 Cl c. K 2 CO 3 d. Cu(NO 3 ) Consider the titration diagram shown on the plot below. What type of substance was originally in the flask? a. weak base b. strong base c. weak acid d. strong acid 21. In which of the following solutions would you expect AgBr to have the highest solubility? a. 0.1 M NaBr b. pure water c. 0.1 M AgNO 3 d M LiBr 22. Calculate ph of a buffer composed of M HClO (K a = 3.0x10 8 ) and 0.1 M KClO. a. 2.6 b. 4.4 c d What is the molar solubility of Zn(OH) 2 (K sp = 3.0x10 16 )? a. 5.2 x 10 4 b. 2.1 x 10 3 c. 4.2 x 10 6 d. 6.7 x What is the oxidation number of Cr in K 2 CrO 4? a. 6 b. 5 c. 2 d Which element is oxidized in the reaction Fe 2 S 3 12HNO 3 2Fe(NO 3 ) 3 3S 6NO 2 6H 2 O a. N b. S c. H d. Fe

10 26. The balanced halfreaction in which the sulfate ion (SO 4 2 ) is reduced to sulfite ion (SO 3 2 ) is: a. a twoelectron processes b. a oneelectron processes c. a fourelectron processes d. a threeelectron processes 27. Respective standard reduction potentials of Sn 2 and Co 2 are V and V, respectively. An electrochemical cell is built from Co electrode in Co 2 solution and Sn electrode in Sn 2 solution. The reduction reaction will occur on the electrode which is called: a. Sn, anode b. Co, anode c. Sn, cathode d. Co, cathode 28. Using the table of standard reduction potentials indicate the metal which could provide cathode protection to Al: a. Ag b. Cu c. Na d. Zn 29. Calculate G 0 (in J) for the reaction Zn Cu 2 Zn 2 Cu (Zn 2 /Zn E 0 red = V; Cu 2 /Cu E o red = V) a. 212 kj b. 340 kj c. 106 kj d. 424 kj 30. Which of the following processes results in an increase in the number of protons in the nucleus? a. alpha emission b. positron emission c. beta emission d. gamma emission 31. Balance the nuclear reaction to identify the identity of the element E: U α E. a. Th b. Np c. Pu d. Pa Pb has a halflife of 22.3 years and decay to produce 206 Hg. If you start with 7.50 g of 210 Pb, how many grams of 206 Hg will you have after 17.5 years? a b c d What of the following condition favors nuclear stability: a. atomic number > 92

11 b. neutrontoproton ration less than 1:2 c. even numbers of protons and neutrons d. chemical inertness 34. Which complex below has 2 unpaired electrons? a. tetrahedral [CoCl 4 ] 2 b. octahedral [Ni(NH 3 ) 6 ] 2 c. squareplanar [Ni(CN) 4 ] 2 d. lowspin octahedral [Fe(CN) 6 ] Based on the spectrochemical series F <NH 3 <NO 2 < CN, which of the complexes below is most likely highspin? a. [Co(NH 3 ) 6 ] 3 b. [CrF 6 ] 3 c. [Co(CN) 6 ] 3 d. [Co(NO) 2 ] What is the coordination number of [Co(en)F 4 ]? a. 5 b. 4 c. 2 d The most common isotope of hydrogen is: a. tritium b. deuterium c. helium d. protium 38. Br 2 can be prepared by combining NaBr with a. NaCl b. Cl 2 c. I 2 d. HBr 39. Which oxide will produce a basic aqueous solution? a. SO 3 b. CaO c. H 2 O d. NO The oxidation state of oxygen in O 2 F 2 is: a. 0 b. 1 c. 1 d. 2

12 Supplementary information p [Pr oduct] N( t) t1 / 2 =, Kc =, ln = kt = t, k r [Reac tant] N(0) t1/ 2 G = H T S E a / RT k = Ae ph = log [H 3 O ], K w = 10 14, poh = log[oh ] [ H 3O ][ A ] K a =, K akb = Kw, pka pkb = pkw = 14 [ AH ] E cell = E red ( cathode) E red ( anode), E = E 0 logq, n 0 0 G = nfe, F = 96500J/Vmol c a [ base] K sp = [ C ] [ A ], ph = pka log [ acid ] Acid Base Strongest HClO 4 ClO 4 acids H 2 SO 4 HSO 4 HI I HBr Br HCl Cl HNO 3 NO 3 H 3 O H 2 O HSO 4 SO 4 H 2 SO 3 HSO 3 Weakest bases

13 H 3 PO 4 H 2 PO 4 HNO 2 NO 2 HF F CH 3 CO 2 H CH 3 CO 2 H 2 CO 3 HCO 3 H 2 S HS NH 4 NH3 3 CN N CO 2 3 S 2 HCN HCO 3 HS H 2 O OH Weakest NH 3 NH 2 acids OH 2 O Strongest bases

Chem 210 Jasperse Final Exam- Version 1 Note: See the very last page to see the formulas that will be provided with the final exam.

Chem 210 Jasperse Final Exam- Version 1 Note: See the very last page to see the formulas that will be provided with the final exam. 1 1. Which of the following liquids would have the highest vapor pressure,