NEETChemistryCarboxylic Acid Derivatives
Assertion: Chloro acetic acid has higher pKa value than Acetic acid. Reason: The - I effect of Cl further stabilises the carboxylate anion formed by the loss of the proton.
Options
- ABoth assertion and reason are correct statements, and reason is the correct explanation of the assertion.
- BBoth assertion and reason are correct statements, but reason is not the correct explanation of the assertion.
- CAssertion is correct, but reason is wrong statement.
- DAssertion is wrong, but reason is correct statement.
Correct answer
D. Assertion is wrong, but reason is correct statement.
Step-by-step solution
- Fact check: - Acetic acid: pKa ( 4.76 ) - Chloroacetic acid: pKa ( 2.86 ) (much lower, hence stronger acid). - Assertion: Chloroacetic acid has higher pKa than acetic acid ( ) False (it has lower pKa). - Reason: The -1 effect of Cl stabilises the carboxylate anion formed after deprotonation ( ) True. Because chlorine is electronegative, it pulls electron density away, dispersing the negative charge on the carboxylate ion, thus stabilising it. This increases acidity (lowers pKa).