Question

The increasing order of the $p{K}_b$ of the following compound is :

• A. $\left(A\right)<\left(C\right)<\left(D\right)<\left(B\right)$
• B. $\left(B\right)<\left(D\right)<\left(A\right)<\left(C\right)$
• C. $\left(C\right)<\left(A\right)<\left(D\right)<\left(B\right)$
• D. $\left(B\right)<\left(D\right)<\left(C\right)<\left(A\right)$

Answer 1

The correct option is B $\left(B\right)<\left(D\right)<\left(A\right)<\left(C\right)$

Order of basicity is $B>D>A>C$

Hence order of $pKb$ values $B<D<A<C$

Basicity $\propto +R\propto \frac{1}{-R}$

$\propto +H\propto \frac{1}{-H}$

As $F$ shows $-I$ effect and $N{O}_2$ shows $-R$ effect