Eduprobe
Question:
Which one of the following statements is correct when SO2 is passed through acidified K2Cr2O7 solution?
The solution turns blue
SO2 is reduced
The solution is decolourized
Green Cr2(SO4)3 is formed
Solution:
When SO2 is passed through acidified K2Cr2O7 solution, green Cr2(SO4)3 is formed. K2Cr2O7 + 3SO2 + H2SO4 → K2SO4 + Cr2(SO4)3 + H2O
Sulphur dioxide is oxidized to sulphuric acid. Potassium dichromate is reduced to chromic sulphate. Orange colour of solution turns green.