Question

With an increase in temperature, the pH of PURE WATER changes right?

Answer 1

the ph of pure water decreases when the temperature increases, so yes it does change

Answer 2

As Temperature increases, pH decreases. This is because you're giving the system (some system with water) energy for the water molecule to absorb - endothermic process.

If you start at zero, and gradually increase to say, room temperautre, in a non complicated manner, what you can essentially think of the reaction as doing is

\(\sf H _2O\) \(\leftrightharpoons\) \(\sf H^+ + OH^-\)

Answer 3

Oh okay! Thanks @abb0t @felipecasal :))
It is also related to Le Chatelier's principle right?
I was just confused because i posted a question about it a few days ago and someone told me the pH remains the same but i was pretty sure that there would be a change in pH.
Anyways thanks so much for clearing it up :)

Answer 4

Yes. You can use Le'Chatlier to explain this in terms of where the equilibrium will proceed.

Answer 5

Just keep in mind that although the pH changes, it will still be neutral, because you have the system at equilibrium. Meaning, you have the same amount of proton and hydroxide ions in the system.

Answer 6

So to sum it all up... It would mean:
As temperature increases, it will favour the forward reaction and is endothermic. Therefore, the concentration of hydronium and hydroxide ions will differ and the system would shift to the left? (i always get confused between shifting to the left or right) to minimise the effects of the disturbance (increase in temperature).
Thus resulting in a decrease in the pH of pure water. However, the pH of water would still remain neutral as [H3O+] = [OH-] at any one temperature.

Answer 7

pretty sure you got it

Answer 8

Thanks again!