Chemistry
The link between pH and pOH
At 25 degrees Celsius the two scales always sum to 14, because the ion product of water is one times ten to the minus fourteen. Knowing one gives the other immediately.
The Formula
pH + pOH = 14
At 25 degrees Celsius the two scales always sum to 14, because the ion product of water is one times ten to the minus fourteen. Knowing one gives the other immediately.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| pH | pH value | dimensionless | The acidity measure computed from hydrogen ions. |
| pOH | pOH value | dimensionless | 14 minus the pH; the alkalinity measure. |
What Each Symbol Means
pHdimensionless
pH value
The acidity measure computed from hydrogen ions.
pOHdimensionless
pOH value
14 minus the pH; the alkalinity measure.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate ph page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate pH, filed under Science. Every number the guide produces comes from substituting into this one line.