Write balanced equation for the following reactions to take place:

(i) Catalytic hydrogenation of ethyne.

(ii) Preparation of ethyne from ethylene dibromide.

(iii) Preparation of ester using carboxylic acid.

(iv) Reaction of sodium with ethanol.

(v) Preparation of ethene using alkylhalide

Aluminium is obtained from alumina:

Answer the following :

(i) Electrolyte used

(ii) Write cathode reaction

(iii) Why anode is replaced

State your observation in each of the following cases :

(i) When dilute hydrochloric acid is added to sodium carbonate crystals.

(ii) When excess sodium hydroxide is added to calcium nitrate solution.

(iii) At the cathode when acidified aqueous copper sulphate solution is electrolyzed with copper electrodes.

(iv) When calcium hydroxide is heated with ammonium chloride crystals.

(v) When moist starch iodide paper is introduced into chlorine gas.

Study the figure given below and answer the questions that follow :

(i) Identify the gas Y.

(ii) What property of gas Y does this experiment demonstrate ?

(iii) Name another gas which has the same property and can be demonstrated through the experiment.