Fourth Exam – Form D Key 1. C 2. B 3. A 4. D 5. E 6. E 7. A 8. C 9. B 10. B 11. D 12. C 13. C3H9N C6H12 14. [sodium ion] = 0.60 M [phosphate ion] = 0.2 M 15. 16. 2 Ag1+(aq) + S2−(aq) ⇌ Ag2S(s) 17. 2 C3H6O2S2 + 13 O2  6 CO2 + 6 H2O + 4 SO3 18. 2 Ag(s) + F2(g) ⇌ 2 Ag1+(aq) + 2 F1−(aq) Eo = +2.07 V 19. a) H OC IHHHH O CHHHI b) CH3I (yes or no) chemical formula a) no none b) yes CuBr c) yes Cr2(CO3)31. Which of the following substances would be most soluble in water? A) Fe2O3 B) CH3(CH2)8NH2 C) CH3OH D) C3H8 2. Consider the following five substances. How many of them would be strong electrolytes? i) C2H6 ii) NiCl2 iii) CH3I iv) H2O v) NaNO2 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) CaF2 produces the fewest fluoride ions, while BaF2 produces the most fluoride ions B) CaF2 produces the fewest fluoride ions, while PbF2 produces the most fluoride ions C) BaF2 produces the fewest fluoride ions, while PbF2 produces the most fluoride ions D) PbF2 produces the fewest fluoride ions, while CaF2 produces the most fluoride ions E) BaF2 produces the fewest fluoride ions, while CaF2 produces the most fluoride ions 4. In which of the following is a sulfur atom in the +2 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) G + J2− ⇌ G2− + J D) Both A and B E) Both B and C 6. In the question above, which is the best reducing agent? A) G B) J C) G2+ D) G2− E) J2− 7. Which of the following unbalanced processes is a three electron reduction? A) ClO2 → ClO1− B) 2 H2O → O2 C) CO → CH3OH D) PH3 → P E) NO → NH3 8. A galvanic electrochemical cell is constructed using the Sn2+/Sn and Fe2+/Fe half reactions. What reaction takes place at the anode? A) Sn → Sn2+ + 2 e1− C) Fe → Fe2+ + 2 e1− B) Sn2+ + 2 e1− → Sn D) Fe2+ + 2 e1− → Fe EGJ9. What is the oxidizing agent in this reaction? H2PO21− + IO1− + OH1− → HPO32− + H2O + I1− A) H2PO21− B) IO1− C) OH1− D) HPO32− E) I1− 10. Consider the SbO1+ / Sb redox couple, which has a reduction potential of +0.21 V. Select the best statement regarding the strengths of Sb and SbO1+. A) Sb is a stronger reducing agent than Zn while SbO1+ is a stronger oxidizing agent than Sn2+ B) Sb is a stronger reducing agent than Br1− while SbO1+ is a stronger oxidizing agent than Mg2+ C) Sb is a stronger reducing agent than Ag while SbO1+ is a stronger oxidizing agent than Cu2+ D) Sb is a stronger reducing agent than Ni while SbO1+ is a stronger oxidizing agent than Ag1+ 11. In the molecule shown, which atom is most likely to act as a Lewis base? A) hydrogen #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 covalent bond B) The Lewis acid provides two electrons to form a new ionic bond C) The Lewis base provides two electrons to form a new covalent bond D) Each reactant contributes one electron to form a new covalent bond E) A positive ion and negative ion come together to form a new ionic 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. N 14. (4 each) What is the concentration of each ion in a 0.20 M solution of sodium phosphate? [sodium ion] = [phosphate 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) MnBr2 and VSO4 b) CuC2H3O2 and KBr c) Li2CO3 and Cr(NO3)3 16. (10) Write a balanced net equation for the reaction that occurs when 0.1 M aqueous solutions of AgNO3 and K2S 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 C3H6O2S2. (For this question, you do not need to show states of matter.) 18. a) (10) Write a balanced net equation for the reaction that occurs when Ag is reacted with F2. Assume the presence of water so aqueous ions can be formed (be sure to include states of matter for this question). b) (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. H OC IHHHH O CHHHI b) (2) Based on your diagram, which reactant is the Lewis acid? (circle one) OH1− CH3I (yes or no) chemical formula a) b)