Weak Acid Strong Base Titration Calculator
Calculate an ideal monoprotic weak-acid titration pH by solving full mass/charge balance, including water equilibrium.
YOUR CALCULATION
Result
—
Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Solve hydrogen concentration on a logarithmic scale, with the weak-acid mass balance, spectator counterion and water ionization included.
H+[Na+]−Kw/H−CT Ka/(Ka+H)=0; CT and [Na+] include dilution
Worked example
25 mL of 0.1 M monoprotic acid titrated by 0.1 M base has stoichiometric equivalence volume 25 mL. Half-equivalence pH is close to pKa but is solved without the buffer shortcut.
Assumptions and input details
Ideal concentration model for a monoprotic acid and fully dissociated monovalent strong base. Ka/Kw must match temperature; no activity correction, polyprotic species, heat, chemical identity or actual laboratory procedure. Curve uses 21 sampled volumes from zero to twice equivalence.
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
The 36 volume definitions distinguish US liquid, US dry and Imperial measures. Cups carry an explicit definition. Japanese shō is 2401/1331 L and a gō is one tenth of it; the explicitly labelled 180 mL rice cup is separate.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
NIST measurement tables · UK Imperial definitions · Japanese traditional units · Mainland China and Hong Kong unit distinctions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
Estimate a conjugate acid/base buffer’s pH before and after a specified strong-acid or strong-base addition.
Convert pH and ion concentrations or model a single strong or weak monoprotic acid/base. Include water autoionization instead of ignoring dilute-solution effects.
Estimate a single titration endpoint bracket from the largest measured absolute pH/volume slope.
Reserved advertising space.