Question

arrange the following in decreasing order of their basic strength C6 h5 NH2,C2 h5 NH2,(C2 h5) 2NH, Nh3

Answer 1

 Considering the inductive effect of alkyl groups, NH3, C2H5NH2, and (C2H5)2NH can be arranged in the increasing order of their basic strengths as:

NH3 <C2H5NH2 <(C2H5)2NH

Again, C6H5NH2 has proton acceptability less than NH3. Thus, we have:

C6H5NH2 <NH3 <C2H5NH2 <(C2H5)2NH

Due to the - I effect of C6H5 group, the electron density on the N-atom in C6H5CH2NH2 is lower than that on the N-atom in C2H5NH2, but more than that in NH3. Therefore, the given compounds can be arranged in the order of their basic strengths as:

C6H5NH2 <NH3 <C2H5NH2C6H5CH2NH2<C2H5NH2<(C2H5)2NH