Question

The pH of 0.1 M solution of cyanic acid (HCNO) is 2.34. Calculate the ionization constant of the acid and its degree of ionization in the solution.

Answer 1

Calculation of degrees of dissociation (α) in solution

pH = 2.34 or log\(\bigg[\frac{1}{H^+}\bigg]\) = 2.34

\(\bigg[\frac{1}{H^+}\bigg]\) = Antilog 2.34 or [H⁺]

= Antilog (-2.34)

[H⁺] = Antilog (3.66) = 4.571 x 10^-3 M

α = \(\frac{[H^+]}{C}\) = \(\frac{(4.571\times 10^{-3}\,M)}{(0.1\,M)}\)

= 4.571 x 10^-2 = 0.04571 M

Calculation of the ionization constant of the acid

[H⁺] = (K_a x C)^1/2

or, [H⁺]² = (K_a x C)