Question

What is pH of pure water at 70o C

Answer 1

7.0

Answer 2

No, the pH isn't 7.0 because Kw is not 1E-14. I looked on the web and didn't find Kw but you need to look up Kw at 70 C. I found it at 10, 20. 30,. 40, 50 and 100 C but not 70 C.
Then (H^+) = sqrt Kw
and pH = -log(H^+).
Kw at 50 is about 5.5E-14 and at 100 it is abou5 50E-14 so I can't even guess at the Kw at 70 C.

Answer 3

slightly less than 7