# pH change with temperature

I understand that the pH of solutions decreases as the temperature increases but is there a reason as to why some solution's pH decreases more than others even if the temperature change is the same?

• Briefly, as pH relies on the equilibrium concentrations of $\ce{H3O+}$ and $\ce{H+}$, the question really boils down to how temperature affects these equilibria for the given compounds. For quantitative analysis there is van't Hoff equation. – andselisk Jan 7 at 14:00