In an aqueous solution, what is the experimentally determined decreasing order of basic strength spe — Amines Chemistry Question

💡 Solution & Explanation

Aqueous basicity is a delicate balance of the +I effect, hydration energy, and steric hindrance. For the small methyl group, hydration stabilization of the conjugate acid heavily favors less substituted amines, overcoming the +I effect of the third methyl group in the $3^\circ$ amine. The resulting balanced order is $2^\circ > 1^\circ > 3^\circ > NH_3$.