Mno42- (1 mole ) in neutral aqueous medium is disproportionate to
A) 2/3 mole of mno4– and 1/3 mole of mno2
B) 1/3 mole of mno4– and 2/3 mole of mno2
Is there is another way to solve this question without balancing and writing the whole equation. Is there is shortcut to do this question by oxidation state only .
Here MnO42- where Mn is in +6 state disproportionates to MnO41- (where Mn is in +7) and MnO2 (where Mn is in+4). So The changes are
+6 -> +7 => 1 unit increase
+6 -> +4 => 2 unit decrease
So to balance the redox process the ratio of number of moles of the species produced should be
MnO42-: MnO2 = 2 :1
So the statement (A) supports above fact