Arrange the following in increasing order of their basic strength :
` CH_3 NH_2 , (CH_3)_2 NH , (CH_3)_3 N, C_6 H_5 NH_2 ,C_6 H_5 CH_2 NH_2`

Explanation

As explained in answer (i), `C_6 H_5 NH_2` is less basic than `C_6 H_5 CH_2 NH_2` and both these amines are less basic than the three methylamines. Out of three methylamines, `(CH_3)_2NH` is more basic than `(CH_3)_3N` due to greater steric hinderance and less solvation of `(CH_3)_3 overset(+ )NH` ion. It is also less basic than `CH_3 NH_2` due to greater steric hinderance and less solvation. Thus, the correct order of basic strength is: ` C_6 H_5 NH_2 lt C_6 H_5 CH_2 lt NH_2 lt (CH_3)_3 NH lt CH NH_2 lt (CH_3)_2 NH`