Question

Give one chemical test to distinguish between the following pair of compounds:

Acetophenone and Benzophenone

Answer 1

Acetophenone and Benzophenone can be distinguished by using the iodoform test. Acetophenone due to the presence of terminal −COCH₃ group will give positive iodoform test and will give yellow coloured precipitate on reaction with alkaline iodine solution. On the other hand, benzophenone will not show an iodoform reaction.

\[\ce{\underset{Acetophenone}{C6H5COCH3} + \underset{Sodium hypoiodite}{3NaOI} -> \underset{Sodium benzoate}{C6H5COONa} + \underset{\underset{(yellow ppt)}{Iodoform}}{CHI3↓} + 2NaOH}\]

\[\ce{\underset{Benzophenone}{C6H5COCH3} + NaOI -> No yellow ppt of CHI3}\]