Give a chemical test to distinguish between NH₃ and HCl.

Give a chemical test to distinguish between SO₂ and Cl₂.

Name a gas that :

(a) turns moist starch iodide paper blue black

(b) turns moist red litmus blue

(c) does not affect acidified K₂Cr₂O₇ paper but turns lime water milky.

(d) affects acidified K₂Cr₂O₇ paper and also turns lime water milky.

What do you observe when CO₂ is passed through lime water first and then a little in excess? Write balanced equations for your observation.