Q.What happens when chloroform reacts with oxygen in the presence of sunlight?

Chloroform (CHCl3), the classic trihaloalkane, is made in the lab by the haloform reaction from ethanol and bleaching powder (a combined source of Cl2 and Ca(OH)2), in three distinct steps: (1) OXIDATION of ethanol to acetaldehyde by Cl2; (2) CHLORINATION of acetaldehyde (three successive Cl2 substitutions) to trichloroacetaldehyde, chloral; (3) HYDROLYSIS of chloral by Ca(OH)2 to give chloroform + calcium formate -- so the very name 'chloroform' comes from this hydrolysis step yielding formic acid/formate. Chloroform is a colourless, sweetish-smelling, burning-tasting liquid whose vapour depresses the central nervous system (hence its historical use as an anaesthetic) -- a use abandoned once its slow aerial OXIDATION in light to the highly poisonous gas phosgene (COCl2) was recognised, which is exactly why chloroform is stored with a little ethanol (which scavenges any phosgene formed) in a dark bottle (which blocks the light that drives th …