m-Chlorobenzaldehyde on reaction with conc. KOH at room temperature gives:

m-Chlorobenzaldehyde on reaction with concentrated KOH at room temperature gives

Phenol with conc. H2_SO_4 at room temperature gives

When acetaldehyde treated with conc. H_2 SO_4 at room temperature gives compound (A). No. of oxygen atoms present in compound (A)

formaldehyde when treated with conc.KOH gives

Pb on reaction with conc. HNO_3 gives

Pb on reaction with conc. HNO_3 gives