Permanganate ion reacts with bromide ion in basic medium to give manganese dioxide and bromate ion. Write the balanced ionic equation for the reaction.

Explanation

Step -1 : The skeletal ionic equation is :
`MnO_(4)^(_)(ao)+Br^(_)(ao)to MnO_(2)(s)+BrO_(3)^(_)(ao)`
Step -2 Assign oxidation numbers for Mn and Br.
-1 +la +5
`MnO_(4)^(_)(ao)+Br^(_)(ao)to MnO_(2)(s)+BrO_(3)(ao)`
This indicates that permanganate ion is the oxidant and bromide ion is the reductant.
Step -3 :
Calculate the increase or decrease in the oxidation number per atom and for the entire. moleculeion in which it occurs. The number units of oxidations change must be equal to the number units of reduction change. If this is not observed then multiply the oxidising agent with the number of units of oxidation and the reducing agent with the number of units of reduction i.e., multiply oxidant `MnO_(4)` by 2 and reductant `Br^(-)` by l.
+7 -1 +4 +3
`2MnO_(4)^(-)(aq)-:Br^(-)(aq)to MnO_(2)(s)+BrO_(3)^(-)(aq)`
know number of units oxidation number of units reduction .
Step- 4,
Adjust the coefficients of products accordingly.
`2MnO_(4)^(-)(aq)+Br(aq)to 2MnO_(2)(s)+BrO_(3)(aq)`
Step -5 :
Add `H^(+)` ions in acid medium of `H_(2)O` molecules in basic medium in the required number to hydrogen atoms deficient side.
Add `H_(2)O` molecules in acid medium or `OH^(-)` ions in . basic medium in the required number to oxygen atoms difficient side. (a)and (b) may be repeated any number of times by hit and trial method until hydro-gen and oxygen atoms are same in num-ber on both the sides of the redox reaction. This reaction is basic medium.
b`2MnO_(4)^(-)(aq)+Br(aq)+H_(2)O(I)`
`to 2MnO_(2)(s)+BrO_(3)^(-)(aq)+2OH^(-)(aq)`