pH is the negative of the logarithm of the H3O+ ion concentration.
pH = - log [H3O+]
, pOH is the negative of the logarithm of the OH- ion concentration.
pOH = - log [OH-]
pH + pOH = 14
what does this mean and what is a logarithm?
The calculation of pH of solution using the above formula will be dealt in higher classes.