Transition and InnerTransition Elements - Result Question 145
####45. Reduction of the metal centre in aqueous permanganate ion involves
(2011)
(a) three electrons in neutral medium
(b) five electrons in neutral medium
(c) three electrons in alkaline medium
(d) five electrons in acidic medium
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Answer:
Correct Answer: 45. $(a, c, d)$
Solution:
- In neutral medium
$$ MnO _4^{-} \rightarrow MnO _2\left(Mn^{7+}+3 e^{-} \rightarrow Mn^{4+}\right) $$
In alkaline medium
$$ MnO _4^{-} \rightarrow MnO _2\left(Mn^{7+}+3 e^{-} \rightarrow Mn^{4+}\right) $$
In acidic medium
$$ MnO _4^{-} \rightarrow Mn^{2+}\left(Mn^{7+}+5 e^{-} \rightarrow Mn^{2+}\right) $$
