This video lecture from Aliphatic Hydrocarbons (F.Sc. second year Chemistry) is the extension of the previous lecture on the preparation of saturated hydrocarbons i.e. alkanes. The method which is discussed is the Decarboxylation or the removal of carbon dioxide from a hydrocarbon containing a carboxyl group –COOH. When sodium salt of Monocarboxylic acid (R-COO-Na) is made to react with soda lime (lime + caustic soda) then an alkane is yielded by substitution of sodium by hydrogen followed by removal of carbon dioxide which further forms sodium carbonate as a side product. 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.