Question

Which of the following reactions are disproportionation reactions?

(a) \[\ce{Cu^{+} -> Cu^{2+} + Cu}\]

(b) \[\ce{3MnO^{-}4 + 4H^{+} -> 2MnO^{-}4 + MnO2 + 2H2O}\]

(c) \[\ce{2KMnO4 -> K2MnO4 + MnO2 + O2}\]

(d) \[\ce{2MnO^{-}4 + 3Mn^{2+} + 2H2O -> 5MnO2 + 4H^{+}}\]

Options

• a, b

• a, b, c

• b, c, d

• a, d

Answer 1

a, b

Explanation:

(a) \[\ce{\overset{+1}{Cu+} -> \overset{+2}{Cu^{2+}} + \overset{0}{Cu}}\]

(b) \[\ce{\overset{+6}{3MnO^{-}4} + 4H^{+} -> \overset{+2}{2MnO^{-}4} + \overset{+4}{MnO2} + 2H2O}\]