The percent ionization in a solution of a weak acid increases as the analytical concentration decreases.

Question

Quizplus · Accepted Answer

This is due to Le Chatelier's principle, which states that when a system at equilibrium is disturbed, it will shift in the direction to counteract the disturbance. In the case of a weak acid, ionization is a reversible reaction and decreasing the concentration of the acid (disturbance) will shift the equilibrium towards the side with more ions, thus increasing the percent ionization.

The Percent Ionization in a Solution of a Weak Acid