Answer:
[tex][OH^-]^2=2.0\times 10^{6}[/tex]
Explanation:
The ionization constant of the water = [tex]4.0\times 10^{12}[/tex] at a temperature of [tex]112\ ^0C[/tex] and pressure of 20 MPa
Water dissociates as;
[tex]H_2O\rightleftharpoons H^++OH^-[/tex]
The expression for the ionization constant is :
[tex]K_w=[H^+][OH^-][/tex]
For pure water,
[tex][H^+]=[OH^-][/tex]
So,
[tex]K_w=[OH^-]^2[/tex]
[tex][OH^-]^2=4.0\times 10^{12}[/tex]
The concentration of the hydroxide ions, [tex][OH^-]^2=2.0\times 10^{6}[/tex].