Final answer:
To determine the acid dissociation constant (Ka) for a weak acid with a given solution concentration and hydronium ion concentration, use the expression Ka = [H+]^2 / [HA]. The calculated Ka for the acid in question with [H+] = 4.6 x 10^-4 M and [HA] = 0.10 M is 2.116 x 10^-6.
Step-by-step explanation:
To determine the Ka for a weak acid when given the concentration of the acid solution and the concentration of hydronium ions ([H+]), we can use the expression Ka = [H+]2 / [HA], where Ka is the acid dissociation constant, [H+] is the concentration of hydronium ions, and [HA] is the initial concentration of the acid before dissociation.
Given that the concentration of the acid solution ([HA]) is 0.10 M and the [H+] is 4.6 x 10-4 M, we can plug these values into the formula:
Ka = (4.6 x 10-4)2 / 0.10
Upon calculating, we will get:
Ka = (2.116 x 10-7) / 0.10 = 2.116 x 10-6