Applying the DNP (Distance, Number, Power) rule of inductive effect, identify the strongest carboxyl — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

The stabilization of the conjugate base prioritizes Distance over Power. Although $-NO_2$ is a stronger $-I$ group than $-Cl$, the chlorine atom in 2-chlorobutanoic acid is adjacent ($\alpha$ -carbon) to the carboxylate, exerting a far stronger stabilizing pull than a distant $-NO_2$ group.