Question

Is a ph = 7.25 solution acidic, basic, or neutral at 0 °c?

Answer 1

Answer is: solution is acidic, because pH value is less than 7,46.
The Kw (the ionic product for water) at 0°C is 0,12·10⁻¹⁴ mol²/dm⁶.
Kw = [H⁺] · [OH⁻].
[H⁺] = [OH⁻] = √0,12·10⁻¹⁴ mol²/dm⁶.
[H⁺] = [OH⁻] = 3,5·10⁻⁸ mol/L.
pH = -log[H⁺].
pH = -log(3,5·10⁻⁸ mol/L).
pH = 7,46; neutral solution on 0°C.