Poh Calculator
Calculator
Results
- pOH
- 3
- pH
- 11
- H⁺ concentration (mol/L)
- 1e-11
Chemistry results
| pOH | 3 |
| pH | 11 |
| H⁺ concentration (mol/L) | 1e-11 |
formula-map diagram
- pOH
- 3
- pH
- 11
- H⁺ concentration (mol/L)
- 1e-11
Formula breakdown
Formula
pOH = −log₁₀[OH⁻]= 3
Note
Simplified model: these results assume ideal behaviour (ideal gases, dilute solutions, complete reactions) and standard textbook constants. Real laboratory values vary with temperature, pressure, purity and activity coefficients. Do not rely on this for safety-critical or analytical work.
More in Chemistry
See all →Frequently asked questions
What is pOH and how does it relate to pH?+
pOH is the negative base-10 logarithm of the hydroxide ion concentration: pOH = -log10[OH-]. At 25°C, pH and pOH always add up to 14, so pOH = 14 - pH.
Why is the pH + pOH = 14 relationship only valid at 25°C?+
That relationship comes from water's ion product constant (Kw = 1.0 x 10^-14 at 25°C), and Kw changes with temperature, so the sum of pH and pOH shifts away from 14 at other temperatures. For most everyday chemistry problems at room temperature, 14 is a safe assumption.
How do I find hydroxide ion concentration from pOH?+
Reverse the logarithm: [OH-] = 10^(-pOH). This is the same relationship as pH and [H+], just applied to hydroxide ions instead of hydrogen ions.
Does a low pOH mean an acidic or basic solution?+
A low pOH means a high hydroxide ion concentration, which corresponds to a basic (alkaline) solution — this is the opposite relationship from pH, where a low value means acidic. It's easy to mix these up, so remember pOH tracks basicity while pH tracks acidity.
When would I calculate pOH directly instead of pH?+
pOH is calculated directly when you know or can measure the hydroxide ion concentration first, such as when working with a strong base whose dissociation gives OH- directly, like NaOH. It's often more convenient than first finding pH and converting.