Basic strength of alkylamines in aqueous phase is not decided by ________.

The basic strength of alkylamines in an aqueous solution is determined by the interplay of three main factors:

1. Inductive effect: The +I effect of alkyl groups increases the electron density on the nitrogen atom, making it more basic.
2. Solvation effect: The conjugate acid formed after accepting a proton is stabilized by hydrogen bonding with water molecules. Greater solvation leads to higher basicity.
3. Steric hindrance: Bulky alkyl groups can hinder the approach of a proton and also decrease the extent of solvation of the conjugate acid.

Hyperconjugation involves the delocalization of electrons from a filled \(\sigma\) orbital to an adjacent empty or partially filled p-orbital or \(\pi\) system. It does not play a role in determining the basic strength of alkylamines.

Answer: Hyperconjugation effect