Answer Posted / falguni patel

We know that
H+ + OH- --> H2O
Equilibrium constant Kw is
[H+] [OH-] = Kw = 1*10^-14
By applying -log on both side
-log [OH-] - log [H+] = 14
We know that pH = -log [H+]
So pH = 14 - (-log [OH-])
From this eq that the higher the concentration of OH- ions, the lower the value of -log[OH-]. If the concentration of OH- ions reaches 1mol/dm3, the value of-log [OH-] is zero, which acc to eq gives pH 14.
If conc exceed from 1 ,-log [OH-] would be negative and pH is grater than 14.

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