How many grammes of NaOH must be dissolved in one litre of the solution to give it a pH value of 12?

Calculate the pH of a solution obtained by mixing 150 mL of 0.1 N - NaOH and 150 ml of 0.2 N - HCl.

How does Arrhenius theory help in comparing the relative strengths of weak acids and weak bases?

Arrange the following in decreasing order of acidic strength:
(i) HOCl (K_a = 3·0 × 10^–8)
(ii) HCN (K_a = 4·0 × 10^–10)
(iii) HNO₃ (K_a = 4·5 × 10^–4)
(iv) HF (K_a = 6·7 × 10^–4)

259. The ionisation constant of acetic acid is 1·74 × 10^–5. Calculate the degree of dissociation of acetic acid in its 0·05 M solution. Calculate the concentration of acetate ion in the solution and its pH. 

It has been found that the pH of a 0.01 M solution of an organic acid is 4.15. Calculate the concentration of the anion, the ionisation constant of the acid and its pK_a.