Question

The reaction whereby a carboxylic acid loses `CO_(2)` is called decarboxylation. It is carried out by heating a mixture of the sodium salt of carboxylic acid and
A. sodium hydroxide
B. sodamide
C. soda-lime
D. soda-ash

Answer 1

Correct Answer - C
`RCOOH+NaOHrarrRCOONa+H_(2)O`
`RCOONa+NaOHoverset(CaO)rarrRH+Na_(2)CO_(3)`
`NaOH` alone may be used in the above reaction but soda-lime `(NaOH+CaO` in the ratio `3:1`) is preferred because `NaOH` is deliquescent ( absorbs moisture from air to such an extent as to dissolve in it) in nature and `CaO` keeps it dry. Moreover, the presence of `CaO` permits the reaction to be carried out at relatively higher temperature to ensure complete decarboxylation.