Identify the correct order of decreasing basic strength for the following aliphatic primary amines: (I) (II) (III)

Step-by-step solution

The basic strength of an amine depends on the availability of the lone pair of electrons on the nitrogen atom for protonation. Electron-donating groups ( +I effect) increase basicity, while electron-withdrawing groups ( -I effect) decrease basicity. In compound (I), the alkyl group (butyl) exerts a +I effect, increasing the electron density on the nitrogen atom. In compound (II), the group attached to the - CH ₂- NH ₂ group contains an sp^2 hybridized carbon. Since an sp^2 carbon is more electronegative than an sp^