Fourth Exam – Form C Key 1. D 2. C 3. C 4. E 5. B 6. C 7. B 8. D 9. B 10. A 11. B 12. B 13. C4H10O C5H10 14. [iron(II) ion] = 0.30 M [nitrate ion] = 0.60 M 15. 16. Cr3+(aq) + 3 OH1−(aq) ⇌ Cr(OH)3(s) 17. 2 C4H8NO + 13 O2  8 CO2 + 8 H2O + 2 NO2 18. Ni(s) + 2 Ag1+(aq) ⇌ Ni2+(aq) + 2 Ag(s) Eo = +1.03 V 19. a) CH3CBrHCHHHOCH3CH3CBrHCHHOCH3H b) C3H7Br (yes or no) chemical formula a) yes SrSO4 b) no none c) yes Cd3(PO4)21. Which of the following substances would be most soluble in water? A) SiO2 B) CaCO3 C) CH3(CH2)10OH D) NH3 2. Consider the following five substances. How many of them would be strong electrolytes? i) FeCl3 ii) C4H10 iii) KNO3 iv) Na2CO3 v) C5H10O5 A) one B) two C) three D) four E) all five 3. When dissolving these solids in water (note their values of Ksp), which is the best statement CaF2, Ksp = 4 x 10-11 BaF2, Ksp = 1 x 10-6 PbF2, Ksp = 3 x 10-8 A) PbF2 produces the fewest fluoride ions, while CaF2 produces the most fluoride ions B) BaF2 produces the fewest fluoride ions, while PbF2 produces the most fluoride ions C) CaF2 produces the fewest fluoride ions, while BaF2 produces the most fluoride ions D) BaF2 produces the fewest fluoride ions, while CaF2 produces the most fluoride ions E) CaF2 produces the fewest fluoride ions, while PbF2 produces the most fluoride ions 4. In which of the following is a sulfur atom in the +3 oxidation state? A) H2S B) H2SO4 C) H2SO3 D) H2S2O3 E) H2S2O4 5. Consider the energy diagram on the right for the chemical species G and J. Which of the following reactions would be extensive? A) G + J ⇌ G2+ + J2− B) G2+ + J ⇌ G + J2+ C) G2− + J ⇌ G + J2− D) Both A and B E) Both B and C 6. In the question above, which is the best oxidizing agent? A) G B) J C) G2+ D) G2− E) J2− 7. Which of the following unbalanced processes is a four electron reduction? A) NO → NH3 B) CO → CH3OH C) ClO2 → ClO1− D) 2 H2O → O2 E) PH3 → P 8. A galvanic electrochemical cell is constructed using the Zn2+/Zn and Pb2+/Pb half reactions. What reaction takes place at the cathode? A) Zn → Zn2+ + 2 e1− C) Pb → Pb2+ + 2 e1− B) Zn2+ + 2 e1− → Zn D) Pb2+ + 2 e1− → Pb EGJ9. What is the oxidizing agent in this reaction? N2 + HPbO21− + H2O → H2N2O2 + OH1− + Pb A) N2 B) HPbO21− C) H2O D) H2N2O2 E) Pb 10. Consider the Co2+ / Co redox couple, which has a reduction potential of −0.28 V. Select the best statement regarding the strengths of Co and Co2+. A) Co is a stronger reducing agent than Cu while Co2+ is a stronger oxidizing agent than Al3+ B) Co is a stronger reducing agent than Ag while Co2+ is a stronger oxidizing agent than Fe3+ C) Co is a stronger reducing agent than Zn while Co2+ is a stronger oxidizing agent than Sn2+ D) Co is a stronger reducing agent than Fe while Co2+ is a stronger oxidizing agent than Zn2+ 11. In the molecule shown, which atom is most likely to act as a Lewis acid? A) oxygen #1 B) carbon #2 C) carbon #3 D) nitrogen #4 12. Which statement most accurately describes a Lewis acid/base reaction? A) The Lewis acid provides two electrons to form a new ionic bond B) The Lewis base provides two electrons to form a new covalent bond C) Each reactant contributes one electron to form a new covalent bond D) A positive ion and negative ion come together to form a new ionic bond E) The Lewis acid provides two electrons to form a new covalent bond PLACE YOUR ANSWERS FOR #13 – 19 DIRECTLY ON THIS EXAM 13. (5 each) In the spaces below, write the chemical formula for each of the molecules. O 14. (4 each) What is the concentration of each ion in a 0.30 M solution of iron(II) nitrate? [iron(II) ion] = [nitrate ion] = O COC NHHH CH2O HH123415. (18) For each combination of 0.1 M aqueous solutions listed, state (yes or no) whether a precipitate will form. IF YES, then provide the chemical formula of the solid. IF NO, write “None” for chemical formula. a) Na2SO4 and SrCl2 b) Cu(C2H3O2)2 and ZnCl2 c) Cd(ClO4)2 and K3PO4 16. Write a balanced net equation for the reaction that occurs when 0.1 M aqueous solutions of CrCl3 and KOH are mixed (be sure to include states of matter for this question). 17. (10) Write a balanced equation with integer coefficients for the complete combustion reaction of C4H8NO. (For this question, you do not need to show states of matter.) 18. (10) Write a balanced net equation for the reaction that occurs when Ni is added to an aqueous solution of Ag1+ (be sure to include states of matter for this question). (4) What is the potential of this reaction? V 19. a) (8) Diagram the following reaction, using curved arrows to indicate electron movement. Lone pairs are not shown, but may need to be taken into account in your diagram. CH3CBrHCHHHOCH3CH3CBrHCHHOCH3H b) (2) Based on your diagram, which reactant is the Lewis acid? (circle one) C3H7Br OCH31− (yes or no) chemical formula a) b)