Question

The dependence of the equilibrium constant of a reaction on temperature is given by the van’t Hoff equation.Therefore, the ratio of the equilibrium constants at two different temperatures is: ln(k_1/k_2)=deltaH/R(1/T_1-1/T_2). calculate the Ph of water at its normal boiling point.

Answer 1

Use the van't Hoff equation and the heat of vaporization of water to calculate Kw at 100 C from the value you know at 25 C. Now, since the water remains pure, it follows that [H+] = [OH-]. Use this fact and your calculated value for Kw to find [H+]. Now use the definition of pH. I get pH = 6.28.