State one relevant observation for the following: When hydrogen sulphide gas is passed through lead acetate solution.

State one relevant observation: When hydrogen sulphide gas is passed through lead acetate solution.

Write down the observation for the following: Hydrogen sulphide gas, is passed through aqueous copper sulphate solution.

State one relevant observation for the following: Platinum is added to aqua-regia.

State one relevant observation for the following: Anhydrous calcium chloride is exposed to air for some time

State one relevant observation for the following: Action of dilute hydrochloric acid on lead, nitrate solution.

State one relevant observation for the following: When ammonia gas is burnt in an atmosphere of excess oxygen.

State one relevant observation for the following reaction : Burning of ammonia in air.

State one observation for each of the following: Excess ammonium hydroxide solution is added to lead nitrate solution.

State one observation for the following : Excess ammonium hydroxide solution is added to lead nitrate solution.

State one observation for each of the following: Excess ammonium hydroxide solution is added to lead nitrate solution.