How this calculator works
Enter acid pka, conjugate base concentration, weak acid concentration. CalcStack applies the displayed formula and reports each intermediate planning value with the units shown.
Formula / method
pH = pKa + log₁₀([A⁻] ÷ [HA])
Worked example
Acetate pKa 4.76 with 0.1 M base and 0.05 M acid gives pH about 5.061.
Assumptions and limitations
Activities are approximated by concentrations and both buffer species are present.
Dilute/strong acids, ionic strength, temperature and buffer capacity are not modeled.