When sulphur dioxide gas is passed through acidified potassium dichromate solution, the colour of the solution changes from :
(1)orange to yellow (2)orange to green
(3) green to orange (4)yellow to green

Correct answer: (2) orange to green

Explanation: Sulphur dioxide reacts with acidified potassium dichromate solution (orange) to produce chromium sulphate (green). Hence, the colour of the solution changes from orange to green.