Q31 / 180 · KCET 2019 · Chemistry

Match the following pKa values.
$\begin{array}{|l|l|} \hline Acid & pKa \\ \hline (a) Phenol & (i) 16 \\ \hline (b) p-Nitrophenol & (ii) 0.78 \\ \hline (c) Ethanol & (iii) 10 \\ \hline (d) Picric acid & (iv) 7.1 \\ \hline \end{array}$

  • A
    $\begin{array}{llll}a & b & c & d\end{array}$
  • B
    \( \begin{array}{llll}a & b & c & d \\ \text { iv } & \text { ii } & \text { iii } & \text { i }\end{array} \)
  • Correct answer
    C
    \( \begin{array}{llll}a & b & c & d \\ \text { iii } & \text { iv } & \text { i } & \text { ii }\end{array} \)
  • D
    \( \begin{array}{llll}a & b & c & d \\ i i & i & i i & i v\end{array} \)

Solution

The compound will be more acidic when its conjugate base is more stable. In case of these given compounds, more the
electron with the drawing group, present more the compound will be more acidic.

Hence, the correct answer is option: 'C'.

Relevant Questions