\[pH+pOH=14\]
Variables
pHpotential of hydrogen
pOHpotential of hydroxide
Description
What is this formula?
This formula relates pH and pOH in aqueous solutions at 25°C. It is based on the ionic product of water and allows the acidity and basicity scales to be converted into one another.
When to use it
Use this formula when either pH or pOH is known and the corresponding value needs to be determined.
Example
A solution has:
pH = 4.50
Formula:
pH + pOH = 14
Substitution:
4.50 + pOH = 14
Result:
pOH = 9.50
The solution has a pOH of 9.50.
Applications
- Acid-base chemistry
- Water treatment
- Environmental analysis
- Laboratory calculations
- Chemical education
- Process control
Note
The relationship pH + pOH = 14 is valid for dilute aqueous solutions at 25°C. At other temperatures, the ionic product of water changes and the sum of pH and pOH may differ from 14.