Similarly the concentration of hydroxide ion, OH-, of a   solution is commonly expressed in term of the pOH of the solution , which is define as the negative logarithm of OH-
pOH = -log ( OH- )
The hydroxide ion concentration can be obtained from   pOH of the solution using the equation :
 (OH-) = 10-pOH      
Additionally the pH and pOH of any aqueous solution are related as are the hydrogen and the hydroxide ion concentration , the relative equation are : 
( H+)(OH-) = 1×10-14                                  pH + pOH = 14