Explain why secondary amines are more basic than primary amines.

Explanation

Basic character of amines is due to the presence of lone pair of electron. On N-atom more the availability of this lone pair, more is basic character.

Alkyl group (R) is an electron donating group, more the number of alkyl groups bonded to N-atom, more is the availability of electron pair on N-atom and hence more is the basic character.