Question

Sodium salts of carboxylic acids on heating with soda lime give alkanes containing_______ than the carboxylic acid.

• A. one carbon more
• B. one carbon less
• C. two carbon less
• D. Either (a) or (b)

Answer 1

Answer: (B)

Sodium salts of carboxylic acids on heating with soda lime (mixture of sodium hydroxide and calcium oxide) give alkanes containing one carbon atom less than the carboxylic acid. This process of elimination of carbon dioxide from a carboxylic acid is known as decarboxylation
$\underset{\text{Sodium ethanoate}}{C{H}_{3}CO{O}^{-}N{a}^{+}}+NaOH\underset{\Delta }{\overset{CaO}{\to }}\underset{\text{Methane}}{C{H}_4+N{a}_{2}C{O}_3}$