How we worked it out
Updated as you change the numbers.
- pH = −log₁₀[H⁺]; pOH = −log₁₀[OH⁻]; pH + pOH = 14 at 25 °C.
Method and assumptions
Uses concentrations as an approximation of activities, fine for dilute solutions. Kw changes with temperature.
Questions
What is [H⁺] at pH 3.5?
3.162 × 10⁻⁴ mol/L.
Sources
Method and figures checked on . Every worked answer on this page is covered by an automated test. Found a mistake? Tell us.