Question

give a chemical test to distinguish between SO2 and CO2 gas, between ZnSO4 and FeSO4.

Answer 1

Carbon dioxide and sulphur dioxide can be distinguished by using acidified potassium dichromate paper. It cannot be distinguish by using lime water as both the gases turns lime water milky.

Answer 2

Answer:

Chemical test to distinguish between SO2 and CO2 gas:

Carbon dioxide gas : Pass the gas through potassium permanganate . There will be no change in Purple colour.

Sulphur dioxide gas :Pass the gas through potassium permanganate .

 The pink colour will turn into colourless.

Chemical test to distinguish between ZnSO4 and FeSO4:

Ferrous sulphate gives dirty green precipitates with ammonium hydroxide solution which is insoluble in excess.

Zinc sulphate reacts with ammonium hydroxide to give ammonium sulphate and white gelatinous precipitate of zinc hydroxide .

Explanation:

• Potassium permanganate (KMnO4) reacts with sulfur dioxide (SO2) and produces manganese sulfate(MnSO4), sulfuric acid and potassium sulfate.  Purple colour of aqueous KMnO4 solution is reduced to colourless during the reaction.

2KMnO4(aq)+5SO2(g)+2H2O(l) → 2MnSO4(aq)+2H2SO4(aq)+ K2SO4(aq)

• When colourless sulfur dioxide gas is sent to dilute aqueous   potassium permanganate solution, purple colour of aqueous solution is decreased and become colourless  due to formation of Mn2+ cations.