The correct increasing order of the acid strength fo acids, butyric acid (I), 2-chlorobutyric acid (II), 3-chlorobutyaric acid (III), 2,2-dichlorobutyric acid (IV) is :

Options

A. `I lt II lt III lt IV `
B. `III lt II lt IV lt I `
C. `I lt III lt II lt IV `
D. ` III lt I lt II lt IV `

Answer

C

Explanation

`underset( (I)) underset("Butyric acid") (CH_3 CH_2 CH_2 COOH), underset((ii))underset(2-"Chlorobutyric acid ")(CH_3 CH_2 underset(CI) underset(|)CH COOH ), underset((iii))underset(3-"chlorobutyric acid ") ( CH_3 underset( CI) underset(|) CH CH_2 CH_2 COOH), underset((IV))underset("1,2-dichlrobutyric acid ") underset( CH_3 -CH_2 underset(CI) underset(|) overset(CI ) overset(|)C-COOH`
electron withdrawing group (CI) increases the acidic stength of carboxylic acid due to -I effect . teh inductive effect decrease with increase in distance .also greater the number of such groups , larger is the acidic strength thus order of increasing acidic strength is
` I lt III lt II lt IV `