Give a simple test to distinguish between the compounds in each of the following paris.

Explanation

a. and b. The aldehyde gives a position Tollens test (Ag mirror). Also in (a), only aldehyde given a precipitate with `H_(2)NOH` or `PhNHNH_(2)`.
c. Only alcohol is oxidised by `CrO_(3)` (colour changes from orange red to green), alternatively, ketone gives a solid oxime or phenyl hydrazone with `H_(2)NOH` or `PhNHNH_(2)`.
d. Only the aldehyde gives a positive Tollens test, ketone gives a positive iodoform test `("precipitate of" CHI_(3))`