This video lecture from Aldehydes and Ketones (F.Sc. second year Chemistry) covers the addition of sodium bisulfite to carbonyl compounds. The reaction follows the mechanism as for base catalyzed Nucleophilic addition. A base generates sulfite ions which act as nucleophiles and attack the electrophilic end of carbonyl group. The pi electrons of the carbonyl double bond abstract a proton from the solution. This mechanism suits all aldehydes and ketones with lower chains (methyl) atleast on a single side. Find more e-learning material and educational video lectures in Urdu at maktab.pk. These videos are free to use for promotional and commercial purpose by keeping the credits to Maktab.