An organic liquid 'A' containing C,H and O with boiling point `78^(@)C`, possessing a rather pleasant odous. On heating with concentrated sulphuric acid gives a gaseous product 'B' with the empirical formula `CH_(2)` 'B' decolourises bromine water as well as alkaline permanganate solution and takes up one mole of `H_(2)` (per mole of B) in presence of finely divided nickel at high temperature. Identify the substances A and B.

Explanation

`(B)` is an unstaurted hydrocarbon because it decolourises `Br_(2)` water and alkaine `KMnO_(4)` soltuions. It contains are `(C=C)` bond because it adds only `1 mol H_(2)//Ni`

Compound `(A)` is `C_(2) H_(5)OH` and with conc: `H_(2)SO_(4), (B)` is obtained.
`underset({:((A)),("Ethanol"):})(C_(2)H_(5)OH)overset("Conc.")underset({:(H_(2)SO_(4)),(-H_(2)O):})toH_(2)Cunderset((B))=CH_(2)`