The increasing order of the pKb of the following compound is:
(C)<(A)<(D)<(B)
(A)<(C)<(D)<(B)
(B)<(D)<(C)<(A)
(B)<(D)<(A)<(C)
Solution:
Order of basicity is B > D > A > C Hence order of pKb values B < D < A < C Basicity ∝ +R ∝ 1 -R ∝ +H ∝ 1 -H As F shows -I effect and NO2 shows -R effect