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Chemistry · PYQ NEET UG 2019(1)
हिन्दीWhich of the following reactions are disproportionation reactions?\n(a) \( 2\text{Cu}^+ \longrightarrow \text{Cu}^{2+} + \text{Cu}^0 \)\n(b) \( 3\text{MnO}_4^{2-} + 4\text{H}^+ \longrightarrow 2\text{MnO}_4^- + \text{MnO}_2 + 2\text{H}_2\text{O} \)\n(c) \( 2\text{KMnO}_4 \xrightarrow{\Delta} \text{K}_2\text{MnO}_4 + \text{MnO}_2 + \text{O}_2 \)\n(d) \( 2\text{MnO}_4^- + 3\text{Mn}^{2+} + 2\text{H}_2\text{O} \longrightarrow 5\text{MnO}_2 + 4\text{H}^+ \)
Correct answer · Option 4
\( \text{(a) and (b) only} \)
Explanation
In disproportionation, a single species is simultaneously oxidized and reduced. (a) Cu(+1) goes to +2 and 0. (b) Mn(+6) in \( \text{MnO}_4^{2-} \) goes to +7 and +4. Both are disproportionation reactions.
