Now recall that we say the pH scale can go up to 14 at temperature of 25°C and up to a concentration of one molar. Because of this, we can calculate pH from POH or vice versa using the following equation. That equation is that pH plus POH equals 14 itself.
In addition to this, we have on the right side some equations that we've seen before where pH equals negative log of H+ and therefore H+ concentration equals 10 to the negative pH. POH equals negative log of OH− and therefore the concentration of OH− equals 10 to the negative POH.
So we're starting quite a collection of different formulas that are connecting pH and POH to one another. Just remember the addition between pH and POH equals 14.
pH + pOH = 14 pH = - log ( H + ) H + = 10 - pH pOH = - log ( OH - ) OH - = 10 - pOH