COMEDK2015ChemistryCarboxylic Acid Derivatives
Which of the following is the correct sequence of relative acidic strength?
Options
- AFCH ₂ COOH > ClCH ₂ COOH > BrCH ₂ COOH
- BClCH ₂ COOH > BrCH ₂ COOH > FCH ₂ COOH
- CBrCH ₂ COOH > ClCH ₂ COOH > FCH ₂ COOH
- DClCH ₂ COOH > FCH ₂ COOH > BrCH ₂ COOH
Correct answer
A. FCH ₂ COOH > ClCH ₂ COOH > BrCH ₂ COOH
Step-by-step solution
Acid strength increases as the electronegativity of halogen increases because the anion formed after H ⁺ ion release, is stabilised by -I -effect. The order of - I -effect is F > Cl > Br > I . Order of acidic strength is as follows : FCH ₂ COOH > ClCH ₂ COOH > BrCH ₂ COOH