Answer in Organic Chemistry for Benjamin ogonyo #120289
April 21st, 2023
pentanoic acid < 5-chloropentanoic acid < 4-chloropentanoic acid < 3-chloropentanoic acid < 2-chloropentanoic acid
RCOOH “leftrightarrow” RCOO– + H+
RCOO– is conjugate base. More stable conjugate base “implies”stronger acid. Acceptors near COO– will stabilize it.
Cl possess +M<-I effects. In that case the conjugation between Cl and COOH is absent. So, only -I effect should be taken into account. Therefore, Cl is strong acceptor in that case.
Since inductive effect operates only through single bonds and are dependent on distance, closer the acceptor to COOH , stronger the acid.