pOH Calculator
Find pOH and pH from hydroxide concentration.
pOH measures basicity from the hydroxide ion concentration.
How the Math Works
The pOH Calculator uses the logarithmic relationship between hydroxide ion concentration and pOH, defined by the equation pOH = -log[OH-]. This means we take the base-10 logarithm of the hydroxide concentration and apply a negative sign. Once pOH is determined, the pH is calculated using the fundamental water relationship pH + pOH = 14, rearranged as pH = 14 - pOH. For example, if [OH-] = 1 x 10^-5 M, then pOH = 5 and pH = 9.
Practical Applications
To use this calculator practically, first measure or obtain the hydroxide ion concentration [OH-] in moles per liter (M). Enter this value into the calculator, which automatically computes pOH using the logarithmic formula. The pH is then derived by subtracting pOH from 14. This is essential for chemists and biology students working with buffer solutions, water quality testing, or studying enzyme activity where pH regulation is critical for proper experimental results.
Day-to-Day Use
Understanding pOH and pH helps explain everyday phenomena like why swimming pool water needs regular testing and adjustment, or why your tap water's pH affects taste and plumbing longevity. It's also relevant when comparing acidic lemon juice to alkaline baking soda in cooking, or understanding how antacids work to neutralize stomach acid. Even simple observations like why some metals corrode faster in certain water conditions relate directly to these pH measurements.
Worked example
[OH⁻] = 10⁻³ → pOH 3, pH 11.
FAQ
Basic solution?
pOH below 7 (pH above 7) means basic.