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.

I got this so far :

Kw = 1.219x 10^-14
[H+]^2= 1.219 x 10^-14
[H+]= -/(1.219) x 10^14
[H+] = 1.104 x 10^-7

pH= -log [H+]
pH= -log [1.104 x 10^-7]
pH= (log 1.104 + log 10^-7)
I don't completely understand how to calculate pH from -log[H+]

1 answer

Look on your calculator, hit the log button and type in 1.104E-7 and hit the enter button or equal button. Then multiply by -1. I get 6.957 which I would round to 6.96.