Answer:
[tex]K_a=\frac{[H^+][A^-]}{[HA]}[/tex]
Explanation:
ka is defined as the dissociation constant of an acid. It is defined as the ratio of concentration of products to the concentration of reactants.
For the dissociation of weak acid, the chemical equation follows:
[tex]HA\rightleftharpoons H^++A^-[/tex]
The equilibrium constant is defined by the equilibrium concentration of products over reactants:
[tex]K_a=\frac{[H^+][A^-]}{[HA]}[/tex]
