Which of the following statement(s) is/are correct? (A) The pH of 1 × 10 – 8 M HCl solution is 8 . (B) The conjugate base of H 2 PO 4 - is HPO 4 2 - . (C) K w increases with increase in temperature. (D) When a solution of a weak monoprotic acid is titrated against a strong base at half neutralisation point, pH = 1 2 pK a . Choose the correct answer from the options given below:

Step-by-step solution

When concentration of H + ion is more than 10 - 7 M , the proton concentration from water must be considered. Hence, the pH of 10 - 8 M HCl solution is not equal to 8. H 2 PO 4 - Acid ⇌ HPO 4 2 - Conjugate base + H + K w increase with increase in temperature as dissociation of water increases with increase in temperature. When weak monoprotic acid is titrated against strong base, at half neutralization point, the solution becomes acidic buffer and its pH is given by pH = pK a + log Salt Acid ⇒ pH = pK a + 0 as salt