From – Ethyne, ethanol, acetic acid, ethene, methane. Choose the one which relates to (i) to (iv).

(i) An unsaturated hydrocarbon used for welding purposes.

(ii) An organic compound whose functional group is carboxyl.

(iii) A hydrocarbon which on catalytic hydrogenation gives a saturated hydrocarbon.

(iv) An organic compound used as a thermometric liquid.

(i) Why is pure acetic acid known as glacial acetic acid?

(ii) Give a chemical equation for the reaction between ethyl alcohol and acetic acid.

Give the structural formula for the following :

(i) Methanoic acid

(ii) Ethanal

(iii) Ethyne

(iv) Acetone

(v) 2-methyl propane.

Identify the gas evolved when : sodium propionate is heated with soda lime.