Redox Reactions And Electrochemistry Ques 773
Question: $ MnO_4^{2-} $ undergoes disproportionation reaction in acidic medium but $ MnO_4^{-} $ does not because
Options:
A) In $ MnO_4^{2-}Mn $ is in intermediate oxidation state
B) In $ MnO_4^{2-},Mn $ is in lowest oxidation state
C) In $ MnO_4^{2-},Mn $ is in intermediate oxidation state
D) None of the above
Show Answer
Answer:
Correct Answer: A
Solution:
[a] In $ MnO_4^{2-}, $ the oxidation number of $ Mn $ is + 6. It can increase its oxidation number (to + 7) or decrease its oxidation number (to + 4, + 3, + 2, 0).
Hence it undergoes disproprotion rection is acidic medium.
In $ MnO_4^{-},Mn $ is in its highest oxidation state i.e., +7. It can only decrease its oxidation number.
Hence, it cannot undergo disproportionation reaction.
