Which row of the table describes what happens when a solution of a weak acid is diluted? (Assume constant temperature.) | K_a | Extent of acid ionisation | |-------------------|--------------------------| | A - HSC - SSCE Chemistry - Question 6 - 2021 - Paper 1

When a weak acid is diluted, the concentration of the acid decreases, leading to an increase in the extent of ionization due to Le Chatelier's principle. This principle states that if a system at equilibrium is disrupted, the system will adjust to counteract the change. In the case of dilution, the equilibrium shifts towards the ionized form, thus increasing the extent of ionization. Therefore, the correct answer is:

C. Remains the same, Increases.