$(I)$ $PhCOOH$
$(II)$ $o-\, NO_2C_6H_4COOH$
$(III)$ $P-\, NO_2C_6H_4COOH$
$(IV)$ $m-\, NO_2C_6H_4COOH$
નીચે આપેલાં ક્રમ માંથી સાચો ક્રમ કયો હશે ?
$\begin{matrix}
O\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\
||\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\
C{{H}_{3}}-C-OH+C{{H}_{3}}-OH\overset{cat.}{\longleftrightarrow} \\
\end{matrix}\begin{matrix}
O\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\
||\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\
C{{H}_{3}}-C-O-C{{H}_{3}}+{{H}_{2}}O \\
\end{matrix}$