MCQ
Which of the following has highest $pK_a$ value
- A$Br-CH_2-CH_2-COOH$
- ✓$CH_3-CH_2-COOH$
- C$\begin{array}{*{20}{c}}
{C{H_3} - CH - COOH}\\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}\\
{Br\,\,\,\,\,\,\,\,\,\,\,}
\end{array}$ - D$\begin{array}{*{20}{c}}
{Br\,\,\,}\\
{|\,\,\,\,\,\,}\\
{C{H_3} - C - COOH}\\
{|\,\,\,\,\,\,\,}\\
{Br\,\,\,\,\,}
\end{array}$
