(a) Give only one suitable chemical test to identify the following gases.
(i) Ammonia
(ii) Sulphur dioxide
(iii) Hydrogen chloride
(iv) Chlorine
(v) Carbon dioxide
(vi) Oxygen
(vii) Hydrogen
(b) Select a basic gas mentioned in Q. 1(a). How is the basic nature suspected?
(c) Select acidic gases from the gases mentioned in Q. 1 (a). How is the acidic nature suspected?
(d) The two gases A and B are bleaching agents. A is greenish yellow and bleaches due to it's oxidising property while B a colourless gas bleaches due to reduction. Identify A and B.
(e) Which gas turns blue cobalt chloride paper light pink?
Give one similarity in test between (i) Cl2 and HCl (ii) SO2 and CO2.
(i) Ammonia — When a glass rod dipped in conc. HCl is brought near the gas, dense white fumes of ammonium chloride are formed.
(ii) Sulphur dioxide — Sulphur dioxide gas turns acidified potassium permanganate from pink to clear colourless and acidified potassium dichromate from orange to clear green.
(iii) Hydrogen chloride — Forms a curdy white ppt. on passage through AgNO3 solution. The precipitate dissolves in excess of NH4OH.
(iv) Chlorine — Chlorine turns moist blue litmus red and then bleaches it.
(v) Oxygen — Oxygen gas rekindles a glowing wooden splinter.
(iv) Hydrogen — Hydrogen gas burns with a 'pop' sound in air.
(b) Ammonia is a basic gas. It turns red litmus blue.
(c) Sulphur dioxide, Hydrogen chloride, Chlorine, Carbon dioxide.
(d) A is Chlorine and B is Sulphur dioxide.
(e) Water vapour
(i) Similarity in test of Cl2 and HCl — Forms a white ppt. on reaction with AgNO3 solution.
(ii) Similarity in test of SO2 and CO2 — Both turn lime water milky.