Relation between Ka and Kb of Conjugate acid-base pair

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For a weak acid (ce{HX}) undergoing ionization in its aqueous solution, produces (ce{H3O+}) and (ce{X-}) ions.

Ionization constant of acid (K_a) for (ce{HX + H2O <=> H3O+ + X-}) is given by (K_c = {left [ ce{H3O+} right ] left [ ce{X-(aq)} right ]^s over {left [ ce{HX(aq)} right ]} })