Question

Kw at certain temperature? at a certain temperature, the ph of a neutral solution is 7.53. what is the value of kw at that temperature?

Answer 1

Remember that pH = -log[H⁺]

So [H⁺] = 10^(-pH)

also recall that Kw for water would be:
Kw = [H⁺][OH⁻]

Remember that in water, the concentration of hydronium ions, or H⁺, will equal the concentration of hydroxide ions. That is [H⁺] = [OH⁻].

[OH⁻] = [H⁺] = 10^(-7.53) = 2.95*10^-8
(The rules for significant digits is when you take 10 to the power of something with x significant decimal places, then the result will have x significant digits. But for now keep some extra digits so we won't have rounding errors.)

Kw = (2.95*10^-8)*(2.95*10^-8) = 8.70*10^-16 = 8.7*10^-16

The Kw is 8.7*10^-16.