Question

The Kw of water varies with temperature. Calculate the pH of water at 46⁰C with a Kw = 1.219 x 10-14. Show all calculations leading to an answer.

Answer 1

Kw is equal to the concentration of the H+ and the OH-. In pure water, the concetration of H+ and the OH- is equal. In computing for the pH of water, we tke the negative log of the concentration of H+. To solve the concentration of H+ we take the square root of the Kw (Since Kw=[H+]*[H+] since [H+]=[OH-])
H+ is equal to 1.104*10^-7
negative log of the H+ conc. or the pH is 6.96 (pH = -log(1.104*10^-7))

The answer is valid and is close to the neutral pH which is 7.