The whole range of pH value

[Wu Yuchen A1]

as pKw remains 14 just if temperature is 25 ℃. What will happen to the whole range of pH if temperature is not at 25 ℃? ( Since pH+pOH=pKw, while pKw does not equal to 14, is that possible for pOH to go below zero or the total range of pH just decreases?)

[Gwyndolyn]

The pH scale does change if the temperature changes. If it were to happen in any of our problems I believe they would give you the Kw value so you could do the problem following the same steps as ones with a temp of 25 ℃. You'd get the pKw value from the given Kw (pKw=-log(Kw)) and then solve the problem normally using these values.