Chemistry - GOC Question with Solution | TestHub

The small-ring ammonium ion $\mathrm{III}$ has a less basic amine conjugate base because its lone pair has increased s character. Morpholine's oxygen withdraws inductively, making $\mathrm{I}$'s conjugate base less basic than piperidine, $\mathrm{II}$. Conjugate-acid strengths therefore follow $\mathrm{III}$ > $\mathrm{I}$ > $\mathrm{II}$.