Choose the weakest acid among the following

Options

A. `F_(3)C - COOH`
B. `F-CH_(2)-COOH`
C. `CH_(3)-COOH`
D. `(CH_(3))_(2)CH-COOH`

Answer

D

Explanation

The acidity of carboxylic acids depends upon the nature of the alkly group attached to -COOH. The presence of an electron-withdrawing (-I effect) group weakens the O-H bond in the acid and increases the acidity, while the presence of an electron releasing (+I effect) group strengthens the O-H bond of acid and thus, decreases the acidity. Thus, the weakest acid is,
`underset("2-methylpropanoic acid")(CH_(3)-overset(CH_(3))overset(|)(CH)-COOH)`