Redox Reactions Question 2
Question 2 - 2024 (01 Feb Shift 1)
Which of the following reactions are disproportionation reactions?
(A) $\mathrm{Cu}^{+} \rightarrow \mathrm{Cu}^{2+}+\mathrm{Cu}$
(B) $3 \mathrm{MnO}{4}^{2-}+4 \mathrm{H}^{+} \rightarrow 2 \mathrm{MnO}{4}^{-}+\mathrm{MnO}{2}+2 \mathrm{H}{2} \mathrm{O}$
(C) $2 \mathrm{KMnO}{4} \rightarrow \mathrm{K}{2} \mathrm{MnO}{4}+\mathrm{MnO}{2}+\mathrm{O}_{2}$
(D) $2 \mathrm{MnO}{4}^{-}+3 \mathrm{Mn}^{2+}+2 \mathrm{H}{2} \mathrm{O} \rightarrow 5 \mathrm{MnO}_{2}+4 \mathrm{H}^{+}$
Choose the correct answer from the options given below:
(1) $(\mathrm{A}),(\mathrm{B})$
(2) (B), (C), (D)
(3) (A), (B), (C)
(4) (A), (D)
Show Answer
Answer (1)
Solution
When a particular oxidation state becomes less stable relative to other oxidation state, one lower, one higher, it is said to undergo disproportionation.
$\mathrm{Cu}^{+} \rightarrow \mathrm{Cu}^{2+}+\mathrm{Cu}$
$3 \mathrm{MnO}{4}^{2-}+4 \mathrm{H}^{+} \rightarrow 2 \mathrm{MnO}{4}^{-}+\mathrm{MnO}{2}+2 \mathrm{H}{2} \mathrm{O}$
