Answer 1

C₆H₅N(CH₃)₂ is more basic than C₆H₅NH₂ due to the presence of the +I effect of two −CH₃ groups in C₆H₅N(CH₃)₂. Further, CH₃NH₂ contains one −CH₃ group while (C₂H₅)₂NH contains two −C₂H₅groups. Thus, (C₂H₅)₂ NH is more basic than C₂H₅NH₂.

Now, C₆H₅N(CH₃)₂ is less basic than CH₃NH₂ because of the−R effect of −C₆H₅ group.

Hence, the increasing order of the basic strengths of the given compounds is as follows:

C₆H₅NH₂ < C₆H₅N(CH₃)₂ < CH₃NH₂ < (C₂H₅)₂NH