1 \(CH_3-CHO\) \(\mathop {\xrightarrow{{(i)\,NaCN/HCl}}}\limits_{(ii)\,{H_2}O/{H^ \oplus }/\Delta } \)
2 \(CH_3 -CHO + Br-CH_2 -COOC_2H_5\) \(\mathop {\xrightarrow{{(i)\,Zn\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}}}\limits_{(ii)\,N{H_4}Cl/HOH\,\,(iii)\,HOH/{H^ \oplus }/\Delta } \)
3 $\begin{array}{*{20}{c}}
{X\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{C{H_2} - C{H_2} - COOH}
\end{array}$ $\xrightarrow{{NaOH/HOH}}$
4 All of these
Explanation:
Treatment of acetaldehyde with sodium cyanide in presence of \(HCl\) gives acetaldhyde cyanohydrin.This is followed by hydrolysis of cyano group in presence of acid to form hydroxy acid as a product which is \(2-\)hydroxy propanoic acid.