Question

The correct statements among the following:

a) At ${25}^{\circ }C$, pH = pOH = 7

b) pH of an acid solution always less than 7 at ${25}^{\circ }C$

c) pH of 0.001 M $C{H}_{3}COOH$ solution is equal to 3 at ${25}^{\circ }C$

d) pH of 0.05 M $H_{2}S{O}_4$ is equal to pH of 0.1 M H Cl solution

• A. a, b and c are correct
• B. a, b and d are correct
• C. c and d are correct
• D. All are correct

Answer 1

The correct option is B a, b and d are correct

a)pH=7 at ${25}^{0}C$

b) Acid solution have $\left[H^{+}\right]$ conc. which makes $-log\left[H^{+}\right]$ less than 7.

c)${10}^{-3}MC{H}_{3}COOH$ will have pH more than 3 as it is a weak acid and dissociation is less.

d) $\left[H^{+}\right]$ in 0.05M $H_{2}S{O}_4=0.05\times 2=0.1$

$\left[H^{+}\right]$ in 0.1 M HCl=0.1

$\therefore [H^{+}{]}_{H_{2}S{O}_4}=[H^{+}{]}_{HCl}$

$p{H}_{\left(HCl\right)}=p{H}_{\left(H_{2}S{O}_4\right)}$

a, b and d are correct

Hence, the correct option is B