Give simple chemical tests to distinguish between the following pairs of compounds.
Benzaldehyde and Acetophenone
Benzaldehyde and acetophenone can be distinguished by the following tests.
Aldehydes respond to Tollen’s test. Benzaldehyde being an aldehyde reduces Tollen’s reagent to give a red-brown precipitate of Cu2O, but acetophenone being a ketone does not.
`C_6H_5CHO + 2[Ag(NH_3)_2]^(+) + 3OH^(-) -> C_6H_5COO^(-) + Ag darr + 4NH_3 + 2H_2O`
Benza;dehyde Tollen's reagent benzoate ion Silver mirror
Acetophenone being a methyl ketone undergoes oxidation by sodium hypoiodite (NaOI) to give a yellow ppt. of iodoform. But benzaldehyde does not respond to this test.
`C_6H_5COCH_3 + 3NaOI -> C_6H_5COONa + CHI_3 + 2NaOH`
Acetophenone Sodium benzoate Iodoform (yellow ppt)
Video Tutorials For All Subjects
- Aldehydes and Ketones - Chemical Reactions of Aldehydes and Ketones - Oxidation