The correct order of decreasing acid strength of trichloroacetic acid (A), trifluoroacetic acid
(B) acetic acid
(C) and formic acid
(D) is:

Options

A. `B gt A gt D gt C `
B. `B gt D gt C gt A `
C. `A gt B gt C gt D `
D. `A gt C gt B gt D `

Answer

A

Explanation

As-I effect increase -COOH group becomes more electron deficient and tendency to lose `H^+` increases and therefore ,acidic strength increases . Hence `CF_3 COOH gt C CI_2 gt COOH gt CH_3COOH `. As +I effect increases acidic strength decrease i.e, `CH_3 COOH lt HCOOH ` . thus correct order `: CF_3 COOH gt C CI_3 COOH gt HCOOH gt HCOOH gt CH_3 COOH `.