Final answer:
The dissociation constant of HOCl is primarily affected by temperature, pH, and concentration. Pressure does not significantly affect the dissociation constant unless there is a change in temperature. The dissociation constant varies with temperature, influencing the pH and thus the acidity or basicity of the solution.
Step-by-step explanation:
The factors that affect the dissociation constant (Ka) of a weak acid such as hypochlorous acid (HOCl) are primarily pH, temperature, and concentration. Changes in pressure do not affect the value of K unless they are associated with changes in temperature. For a specific weak acid at equilibrium, the relationship between the acid (HA) and its conjugate base (A-) concentrations, alongside their respective dissociation constant (Ka), are given by the Henderson-Hasselbalch equation: pH = pKa + log([A-]/[HA]). Dissociation constants do vary with temperature; for instance, Ka varies from 1.15 × 10∕ at 0 °C to 4.99 × 10∓ at 100 °C. Moreover, the ion product of water, Kw, is also crucial in these calculations as it equals to 1.0 × 10∔ at 25 °C and determines whether a solution is acidic, basic, or neutral based on the pH, which is a measure of [H3O+].