Given below are few mixtures formed by mixing two components. Which of the following binary mixtures will have same composition in liquid and vapour phase? (i) Ethanol + Chloroform (ii) Nitric acid + Water (iii) Benzene + Toluene (iv) Ethyl chloride + Ethyl bromide

The question is indirectly asking which binary mixture will form, azeotrope (i) and (ii) form azeotrope (iii) and (iv) do not. In option a A-B interactions are stronger then A-A and B-B interactions present in the given 2 liquids forming the solution. Due to stronger A-B interactions, the escaping tendency of A and B types of molecules from the solution have a partial pressure less than expect on bases of Raoult’s Law. The interaction between 2 H O and 3 HNO is stronger than the interaction between 3 3 HNO HNO and 2 2 H O H O due to hydrogen bonding. Thus it shows negative deviation fro