pOH Calculation Calculator
Measure of hydroxide ion concentration.
Formula first
Overview
The pOH is a measure of the hydroxide ion concentration in an aqueous solution, indicating its relative alkalinity. It is calculated as the negative base-10 logarithm of the molar concentration of hydroxide ions, providing a logarithmic scale that complements the pH scale.
Symbols
Variables
pOH = pOH Value, [OH^-] = Concentration OH-
Apply it well
When To Use
When to use: Use this equation when analyzing the basicity of a solution or when the concentration of hydroxide ions is known. It is particularly helpful in calculations involving strong bases where the dissociation is complete and the base concentration directly informs the hydroxide levels.
Why it matters: Understanding pOH is essential for determining the pH of basic substances through the relationship pH + pOH = 14 at 25°C. This calculation is critical in fields such as wastewater treatment, pool chemistry, and the manufacturing of industrial cleaning agents.
Avoid these traps
Common Mistakes
- Forgetting the negative sign.
- Confusing pOH with pH.
One free problem
Practice Problem
A specialized cleaning solution is found to have a hydroxide ion concentration of 0.005 M. Calculate the pOH of the solution.
Solve for:
Hint: Apply the negative base-10 logarithm to the provided concentration value.
The full worked solution stays in the interactive walkthrough.
References
Sources
- Atkins' Physical Chemistry
- IUPAC Gold Book: p-function
- Chemistry: The Central Science by Brown, LeMay, Bursten, Murphy, Woodward, Stoltzfus
- Wikipedia: pOH
- IUPAC Gold Book (pH)
- IUPAC Gold Book: pOH
- Wikipedia: pH
- Wikipedia: Activity (chemistry)