pH and Acid-Base Calculator
Calculate pH, pOH, [H⁺], [OH⁻], and acid/base classification for aqueous solutions at 25°C.
dimensionless (0–14)
Results will appear here.
Formulas Used
Core relationships (at 25°C, Kw = 1×10⁻¹⁴):
Weak acid (exact quadratic):
Weak base (exact quadratic):
Assumptions & References
- All calculations assume dilute aqueous solutions at 25°C (298.15 K).
- The weak acid/base model uses the exact quadratic formula, not the 5% approximation, ensuring accuracy at all concentrations.
- References: Atkins & de Paula, Physical Chemistry, 10th ed.; Zumdahl, Chemistry, 9th ed.; IUPAC recommendations for pH (2002).