Question

Which of the following compound is the most acidic?

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

Option (a) is the most acidic as the nitro group $(-N{O}_2)$ which is -I group is nearest to the carboxylic group, thus increasing the stability of the anion formed after the removal of the $H^{+}$ion.
Thus, $\alpha$- nitro acetic acid is more acidic than other compounds because -I effect of nitro group is more than that of chloro group.