pH & pOH Calculator
pH & pOH is evaluated from pH, pOH and [H⁺] concentration. The calculation reports pH, pOH and [H⁺].
Results
About the pH & pOH Calculator
The calculator uses a multi formula configuration. Each reported value is read as a direct evaluation of the stored rules with the declared field formats and units.
Formula basis:
pH = - log₁₀[H⁺]
pOH = - log₁₀[OH⁻]
pH + pOH = 14 (at 25 degC)
[H⁺] = 10⁻ᵖᴴ
[OH⁻] = 10⁻ᵖᴼᴴ
Kw = [H⁺][OH⁻] = 10⁻¹⁴ = 1 x 10⁻¹⁴ mol^2/L^2
Interpret the outputs in the order shown by the result fields. Optional inputs affect only the outputs that depend on those variables.
Formula & How It Works
The calculation applies the following relations exactly as recorded in the metadata: pH = - log₁₀[H⁺] pOH = - log₁₀[OH⁻] pH + pOH = 14 (at 25 degC) [H⁺] = 10⁻ᵖᴴ [OH⁻] = 10⁻ᵖᴼᴴ Kw = [H⁺][OH⁻] = 10⁻¹⁴ = 1 x 10⁻¹⁴ mol^2/L^2 Each output field is produced by substituting the supplied inputs into the relevant relation and then applying the declared rounding or text format.
Worked Examples
Example 1: Coca-Cola pH
Inputs
With pH = 2.5 as the stated inputs, the result is pH = 2.5, pOH = 11.5 and [H⁺] = 0.00316228 mol/L. Each value corresponds to the declared output fields.
Example 2: Human Blood pH
Inputs
With pH = 7.4 as the stated inputs, the result is pH = 7.4, pOH = 6.6 and [H⁺] = 0.00000004 mol/L. Each value corresponds to the declared output fields.
Example 3: From [H⁺] Concentration
Inputs
With [H⁺] concentration = 0.000003 as the stated inputs, the result is pH = 5.5, pOH = 8.5 and [H⁺] = 0.00000316 mol/L. Each value corresponds to the declared output fields.
Example 4: Swimming Pool Water Check
Inputs
With pH = 7.6 as the stated inputs, the result is pH = 7.6, pOH = 6.4 and [H⁺] = 0.00000003 mol/L. Each value corresponds to the declared output fields.
Common Use Cases
- Convert hydrogen ion concentration to pH
- Find pOH from pH using pH + pOH = 14
- Determine if a solution is acidic or basic from pH