How does the percent ionisation of a given weak acid change as its solution is made more concentrated?

1. Percent ionisation is a ratio, with the initial concentration sitting in the denominator. 2. The ionisation constant fixes the hydronium concentration as roughly the square root of the product of the constant and the start. 3. A square root grows more slowly than the concentration itself does. 4. So the numerator of the ratio lags behind the denominator as the solution is concentrated. 5. The ratio therefore falls, even though the absolute number of ionised molecules rises. 6. The constant stays fixed at a given temperature, so a steady percentage is impossible. 7. This is why percent ionisation must always be quoted alongside a concentration. _Source: OpenStax Chemistry (CC BY 4.0), Ch 14 "Acid-Base Equilibria", section 14.3 Relative Strengths of Acids and Bases_