Calculating pH of a known molarity for an acidic solution

To calculate the pOH of a solution you need to know the concentration of the hydroxide ion in moles per liter (molarity). The pOH is then calculated using the expression:

pOH = - log [OH-]

Example: What is the pOH of a solution that has a hydroxide ion concentration of 4.82 x 10-5 M?

pOH = - log [4.82 x 10-5] = - (14 - 4.32) = 9.68