REDOX Reactions Multiple Choice Test
Click in the appropriate box for each question, then click "Done" at the bottom. 10 marks for each correct answer. Hints cost 5 marks each.
1. What is the oxidation number of copper in Cu+2? 0 1 2 -1 -2
2. What is the oxidation number of Br in the BrO3- ion? -1 1 +5 -5 +7
3. What kind of reaction is Cl2 ® Cl- + ClO2 (aside from unbalanced)? An oxidation A reduction A disproportionation An impossible reaction None of these
4. In the reaction HNO2 + I- ® NO + I3-, what atoms are being oxidized and reduced, respectively? O, I O, I I, N N, I N, O
5. What is the next step in balancing the half reaction Cr2O7-2 ® 2 Cr+3? Add 7 H2O to the right Add 7 H2O to the left Add 3.5 O2 to the left Add 8 electrons to the left Multiply through by 2
6. What is the next step in balancing the reaction SO3-2 + H2O ® SO4-2 + 2 H+ ? Add 3 H2O to the left Add 2 electrons to the left Add 2 electrons to the right Multiply through by 2 Nothing - it is balanced
7. What is the next step in balancing the REDOX reaction having the two half reactions: Cr(OH)4- ® CrO4-2 +4 H+ + 3 e- and ClO- + 2 H+ + 2 e- ® Cl- + H2O ? Add the two half reactions Multiply both by 3 Multiply the oxidation by 2 and the reduction by 3 Multiply the oxidation by 3 and the reduction by 2 Finish balancing the reduction reaction
8. What is wrong with the REDOX reaction 2 Cl- + 2 Br - ® Cl2 + Br2 ? Nothing Nothing is being oxidized Nothing is being reduced Chloride can not be oxidized Bromide can not be oxidized
9. When the balanced reaction 2 MnO4- + SO3-2 + H2O ® 2 MnO4-2 + SO4-2 + 2 H+ is changed to be balanced in basic solution, the result is: 2 MnO4- + SO3-2 ® 2 MnO4-2 + SO4-2 + H2O 2 MnO4- + SO3-2 + 2 OH- ® 2 MnO4-2 + SO4-2 + H2O 2 MnO4- + SO3-2 ® 2 MnO4-2 + SO4-2 + H2O + 2 OH- 2 MnO4- + SO3-2 + H2O ® 2 MnO4-2 + SO4-2 + 2 H+ + 2 OH- 2 MnO4- + SO3-2 + 2 OH- ® 2 MnO4-2 + SO4-2 + H2O + 2 OH-
10. What are the oxidation numbers of the V, O and Cl atoms in VOCl3? -5, -2, -1 -5, +2, -1 +5, -2, +1 +4, -1, -1 +5, -2, -1