QQuestion
State one relevant observation for each of the following:
(a) To the copper nitrate solution, initially few drops of sodium hydroxide solution is added and then added in excess.
(b) Burning of ammonia in excess of oxygen.
(c) Dry ammonia gas is passed over heated PbO.
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(a) A light-blue precipitate of copper(II) hydroxide is formed. It remains insoluble in excess sodium hydroxide solution.
(b) Ammonia burns with a greenish-yellow flame, forming nitrogen and water vapour.
(c) The buff-yellow lead(II) oxide is reduced to grey metallic lead.
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