Amines — Chemistry STD 12 Science — Question

3. CH_3​CH₂​NH₂

Explanation:

The basicity of the among compounds is due to the presence of lone pair on Nitrogen.

CH₃​CH₂​NH_2​ is more basic than NH₃​ because of electron-donating group in CH₃​CH₂​NH₂​ increases the electron density on nitrogen atom.

CH_3​NH₂​ is less basic than CH₃​CH_2​NH₂​ because of ethyl group present in ethylamine which increases electron density on N in ethylamine and attracts H⁺ better than methylamine.

C_6​H₅​NH₂​ is less basic than ethylamine because in C₆​H₅​NH₂​ the lone pair of electron on nitrogen is less available for protonation. It is delocalised into the Benzene ring by resonance.

In ethylamine no such delocalisation takes place.

Hence, among them CH₃​CH₂​NH₂​ is most basic.