Chemistry topic
Acids, Bases & Equilibrium
Calculate ion concentrations, pH, buffers, and chemical equilibria.
Calculators
pH CalculatorCalculate pH, pOH, and ion concentrations for strong or weak acids and bases.pOH CalculatorCalculate pOH, pH, and ion concentrations for strong or weak acids and bases.Henderson-Hasselbalch CalculatorCalculate pH, pKa, acid amount, or conjugate-base amount for a buffer.How Does a Buffer Solution Resist Change in pHA buffer resists pH change because its conjugate base neutralizes added acid and its weak acid neutralizes added base. Test it below.Equilibrium Constant CalculatorBuild the equilibrium expression and calculate K from species activities.Reaction Quotient CalculatorCalculate Q, compare it with K, and predict the reaction direction.
Core relationships
These equations form an accessible map of the quantities used across this topic.
- pH = −log[H⁺]
- pH = pKₐ + log([A⁻]/[HA])