The compound that undergoes decarboxylation most readily under mild conditions is:

$CH_3CH_2COOH$ $\xrightarrow{Br_2/P} X$ $\xrightarrow{NH_3} Y$. What is $Y$ in the above reaction?

The major product in the reaction is:

Saponification of ethyl benzoate with caustic soda as alkali gives:

What is the order of reactivity of the following compounds towards sodalime decarboxylation?
$(i)$ $m$-nitro-phenylacetic acid
(ii) $p$-nitro-phenylacetic acid
(iii) $p$-methoxy-phenylacetic acid
(iv) $p$-methyl-phenylacetic acid

Oxalic acid when reduced with zinc and $H_2SO_4$ gives