Question

When so2 is passed in acidified k2cr2o7 solution oxidation state of s changed from?

Answer 1

· Reaction of sulphur dioxide with K2Cr2O7 in acidic medium is given as. ... Popular questions from Redox Reactions. ... no of moles of MnO4- required to oxidise one mole of ferrous 

Answer 2

To be an oxidation there must be a reduction.  

We look what happen to K2Cr2O7(potassium dichromate- acidified) the overall reaction will be

SO2 + K2Cr2O7 + 3H2SO4 → K2SO4 + Cr2(SO4)3 + 3H2O  

It is a oxidation reaction.

It means the S in SO2 becomes reduced

This is the half reaction

SO2 + 2(H20) ➡ (SO4)²- + 4H+ 2e

Here SO2 becomes (SO4)²-

If X is the oxidation number of S atom we can write as follow.

X + 4(-2) = -2

X - 8 = -2

X = +6

Oxidation state of sulphur becomes +6

i.e., from +4 to +6