How will you distinguish:
Benzaldehyde and acetophenone

Explanation

Benzaldehyde `(C_(6)H_(5)CHO)` and Acetophenone `(CH_(3)COC_(6)H_(5))`.
Benzaldehyde is an aromatic aldehyde while acetophenone is a methyl ketone. These may be distinguished as follows.
(a) Iodoform test. Acetophenone, due to the presence of `CH_(3)CO` group will give iodoform test with `(NaOH + I_(2))` while benzaldehyde will not give this test.
`underset("Acetophenone")(CH_(3)COC_(6)H_(5)) + underset(("Form NaOH " + I_(2)))(3NaOI) rarr C_(6)H_(5)COONa + underset("Iodoform (yellow ppt.)")(CHI_(3)) + 2NaOH`
`underset("Benzaldehyde")(C_(6)H_(5)CHO) + NaOI rarr` No yellow ppt.
(b) Silver mirror test. Benzaldehyde, being an aromatic aldehyde, will reduce Tollen.s reagents to silver (However, it will not give. Fehling.s solution test). ON the other hand, actophenone, a ketone, will not this test.
`underset("Benzaldehyde")(C_(6)H_(5)CHO) + underset("Tollen.s reagent")(2[Ag(NH_(3))_(2)]^(+)) + 3OH^(-) rarr C_(6)H_(5)COO^(-) + 4NH_(3) + underset("Silver mirror")(2Ag) + 2H_(2)O`
`underset("Acetophenone")(CH_(3)COC_(6)H_(5))` + Tollen.s reagent `rarr` No action.