Question

The basic character of amines is due to:
A: Tetrahedral structure
B: Presence of nitrogen atom
C: Lone pair of electron on the nitrogen atom
D: High electronegativity of nitrogen

Answer 1

Hint: Bases are the substances which release $O{H^ - }$ ions when dissolved in water. Amines are compounds that contain nitrogen atoms with a lone pair. Basically amines are derivatives of ammonia. The chemical formula of ammonia is$N{H_3}$.

Complete answer: We know bases are the substances which release $O{H^ - }$ions when dissolved and amines are ammonia derivatives. We have to find out why amines are basic in nature. Basicity is the measure of how easily a compound is able to donate electrons. To donate electrons there must be free electrons to donate. We all know that nitrogen has an extra lone pair and basic character is defined as the ease to donate electrons. So, the presence of lone pairs on nitrogen atoms is the reason for the basic character of amines.

So, the answer to this question is option C, which is Lone pair of electrons on nitrogen atoms.

Additional information: There are two types of groups, one is electron-donating and the other is electron-withdrawing. The electron-donating group provides electrons to the atom with which they are joined thus increasing the basic character (as they are providing electrons) and electron-withdrawing groups take electrons from the atom with which they are joined thus increasing the acidic character.


Note:
Delocalization of charge decreases the ability of compounds to donate electrons and make them less basic. The larger the size of an atom more easily that atom will donate electrons (due to less nuclear pull).