Question

The most acidic compound among the following is :

• A. $C{H}_{3}C{H}_{2}OH$
• B. $C_6{H}_{5}OH$
• C. $C{H}_{3}COOH$
• D. $C{H}_{3}C{H}_{2}C{H}_{2}OH$

Answer 1

Answer: (C)

$C{H}_{3}COOH$ is the most acidic.

The strength of carboxylic acids is known to vary based on their total power to withdraw electrons from the atoms that are bonded to the carboxyl group. When the substituent group has more electron-withdrawing power, the stronger the acid will be. The acidic strength is decreased by the electron-releasing group. This is because the release of protons then gets hindered, and the release of electrons is favored.

$p{K}_a$ of $C{H}_{3}C{H}_{2}OH=16$

$p{K}_a$ of $C_6{H}_{5}OH=10$

$p{K}_a$ of $C_{3}COOH=4.76$

$p{K}_a$ of $C{H}_{3}C{H}_{2}C{H}_{2}OH=16.1$

Hence, from the above data, it is clear that $C{H}_{3}COOH$ is more acidic, because when the $p{K}_a$ value is less, the compound is more acidic .

Hence , option C is correct .