What is the reaction that happened between the acidified dichromate paper and the gas sulphur dioxide and what is the name of the compound that has the blue colour?
Sulphur dioxide gas changes acidifed Potassium Dichromate solution from orange to green. Chemical reaction: Sulphur dioxide reacts with acidified potassium Dichromate solution to give Chromium Sulphate , Poatssium sulphate and water.