Question

balance the following in basic medium mno4 + so2 gives Mn2 + HSO4

Answer 1

Answer:

Well the reduction is relatively easy, and it proceeds with a dramatic colour change from purple to colourless… Mn(+VII)→Mn(+II) …and the difference in oxidation numbers is taken to be the NUMBER of electrons transferred … electrons are LOST upon oxidation, i.e. an INCREASE in oxidation number, but GAINED in reduction, i.e. a electrons are gained by the species undergoing reduction…

MnO−4+8H++5e−→Mn2++4H2Oreduction of permanganate

And sulfur dioxide is OXIDIZED to bisulfate, i.e. S(+IV)→S(+VI) …

SO2+2H2O→HSO−4+3H++2e−oxidation of sulfur dioxide

We take TWO of the former and FIVE of the latter…

2MnO−4+16H++5SO2+10H2O+10e−→2Mn2++8H2O+5HSO−4+15HAnd we cancel away….

2MnO−4+H++5SO2+2H2O→2Mn2++5HSO−4

Which I think is balanced with respect to mass and charge…but it is your problem mate…. And what would we observe in the reaction? The deep purple-red colour of permanganate dissipates to give colourless Mn2+ ion…