Question

A solution of weak acid HA containing 0.01 moles of acid per litre of solutions has pH = 4. The percentage degree of ionisation of the acid and the ionisation constant of acid are respectively
A. `1%, 10^(-6)`
B. `0.01%, 10^(-4)`
C. `1%, 10^(-4)`
D. `0.01%, 10^(-6)`

Answer 1

Correct Answer - A
`H^(+) = C alpha`
`alpha = (H^(+))/(C) = (10^(-4))/(10^(2)) = 10^(-6)`.