State one appropriate observation for each of the following: Electricity is passed through molten lead bromide.

State one appropriate observation for each of the following: Copper sulphide is treated with dilute hydrochloric acid.

State one appropriate observation for the following: Dilute hydrochloric acid is added to copper carbonate.

State one appropriate observation for the following: When a piece of aluminium is anodised.

State one appropriate observation for each of the following: A few drops of dilute hydrochloric acid are added to silver nitrate solution, followed by addition of ammonium hydroxide solution.

State one appropriate observation for the following: Excess of chlorine gas is reacted with ammonia gas.

State one appropriate observation for the following: When dilute hydrochloric acid is added to calcium carbonate crystals.

State one appropriate observation for the following: When dilute hydrochloric acid is added to sodium carbonate crystals.

State one relevant observation for each of the following reactions : Water is added to anhydrous copper sulphate

State the observation for each of the following: Dilute hydrochloric acid is added to lead nitrate crystals.

State one appropriate observation for the following: Concentrated sulphuric acid is added drop wise to a crystal of hydrated copper sulphate.