Quiz Redox Rx 3

1.Which type of reaction is occurring when a metal undergoes corrosion?a. oxidation-reduction b.neutralization c.polymerization d.saponification

2. Given the redox reaction:     2I-(aq) + Br2(l) -> 2Br-(aq) + I2(s) What occurs during this reaction?

a. The I- ion is oxidized, and its oxidation number increases. b. The I- ion is oxidized, and its oxidation number decreases. c. The I- ion is reduced, and its oxidation number increases. d. The I- ion is reduced, and its oxidation number decreases.

3. Which half-reaction correctly represents reduction?a.Cr3+ + 3e- -> Cr(s) b.Cr3++ -> Cr(s) + 3e- c.Cr(s) -> Cr3+ + 3e- d.Cr(s) + 3e- -> Cr3+

4. Which quantities are conserved in all oxidation-reduction reactions?a. charge, only b. mass only c. both charge and mass d. neither charge and mass

5. When a substance is oxidized, ita. loses protons b. gains protons c. acts as an oxidizing agent d. acts as a reducing agent

6. What is the oxidation number of chromium in Cr2O 2- 7 ion ?A) +14 B) +7 C) +3 D) +12 E) +6

7. Which of the following reactions is a redox reaction?(a) K2CrO4 + BaCl2 → BaCrO4 + 2KCl(b) Pb22+ + 2Br- → PbBr(c) Cu + S → CuSa. only a b. only b c. only c d. b and c

8. Which substance is the reducing agent in the following reaction?Fe2S3 + 12HNO3 → 2Fe(NO3)3 + 3S + 6NO2 + 6H2OA) HNO3 B) H2O C) Fe2S3 D) S

Which one of the following types of elements is most likely to be a good oxidizing agent?A) alkali metals B) transition elements C) halogens D) alkaline earth elements

9. Which one of the following reactions is a redox reaction?A) NaOH + HCl → NaCl + H2O B) AgNO3 + HCl → HNO3 + AgCl

C) H2O + NaCl → NaOH + HCl D) None of the above is a redox reaction.

10. What substance is the oxidizing agent in the reaction below.Cr2O72- + 6S2O32- + 14H+ → 2Cr3+ + 3S4O62- + 7H2O

A) Cr3+ B) S2O32- C) H+ D) Cr2O72- E) S4O62-

11. What is the oxidation number of N in NH2OH ?a) -2 b) -1 c) 0 d) +1