Question

Match the List I and List II

List I	List II
(A)The limits of pH values of buffer solution	(i) $5\times {10}^{-12}$
(B) Concentration of $\left[H_3{O}^{+}\right]$ in $0.001M$ $Ba{\left(OH\right)}_2$	(ii) Equal
(C) The buffer capacity of a solution is maximum when concentration of salt to that of acid is	(iii) ${10}^{-14}$
(D) Ionic product of water is	(iv) $p{K}_a\pm 1$

• A. A-(iv); B-(ii); C-(i); D-(iii)
• B. A-(iv); B-(i); C-(iii); D-(ii)
• C. A-(i); B-(iv); C-(ii); D-(iii)
• D. A-(iv); B-(i); C-(ii); D-(iii)

Answer 1

The correct option is D A-(iv); B-(i); C-(ii); D-(iii)

(A) The limits of pH values of buffer solution is $p{K}_a\pm 1$.

Here $p{K}_a$ is dissociation constant.

(B) Concentration of $\left[{H_{3}O}^{+}\right]$ in $0.001MBa{\left(OH\right)}_2$ is $=\frac{Kw}{\left[O{H}^{-}\right]}=\frac{{10}^{-14}}{0.002}=5\times {10}^{-12}M$

(C) The buffer capacity of a solution is maximum when the concentration of salt to that of acid is equal.

$pH=pKa+log\frac{\left[Salt\right]}{\left[Acid\right]}=pKa$

(D) Ionic product of water is ${10}^{-14}$.

$\Rightarrow K_w=\left[H^{+}\right]\left[{OH}^{-}\right]={10}^{-7}\times {10}^{-7}={10}^{-14}$

Hence the correct answer is $A-\left(iv\right),B-\left(i\right),C-\left(ii\right),D-\left(iii\right)$.