Tests of benzaldehyde - aldehydes and ketones
(a) It forms a white precipitate with   solution.
(b)  It creates a yellow precipitate with 2: 4 dinitrophenyl hydrazines.
(c) It provides pink colour with Schiff's reagent.
(d) It creates black precipitate  or silver mirror with Tollen's reagent.
(e) It on reaction with alkaline KMnO4 and subsequent acidification gives a white precipitate of benzoic acid on cooling.