How the colour changes when the gases after thermal decomposition of ferrous sulphate come in contact with an acidified solution of potassium dichromate?
(a) Green to orange
(b) Red to colorless
(c) Orange to green
(d) Blue to green
Due to acidic nature, sulphur dioxide gas turns moist litmus paper from blue to red. It also changes the orange colour of acidified potassium dichromate solution to green.