This video lecture from Aldehydes and Ketones (F.Sc. second year Chemistry) covers the laboratory and industrial preparation of acetaldehyde or ethanal. In laboratory ethyl alcohol is oxidized with acidified dichromate solution and heated. Dry distillation of calcium salts of formic and acetic acid also yields acetaldehyde. Hydration of ethyne is another way of obtaing the same product. Wacker process is used industrially where ethylene is oxidized in air using palladium chloride catalyst over cupric chloride promoter. 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.