Results
How it’s calculated
Teacher Notes
FAQ
What concentration calculations does this tool support?
It supports molarity, mass percent (w/w), mass/volume percent (w/v), M1V1 dilution, same-solute mixing, and w/w% to molarity conversion. Each mode shows unit conversions and key steps.
Which assumptions are used for the pH modes?
Strong acid/base modes use Kw = 1.0×10^-14 at 25 °C. Weak modes show both exact and √(K·C) approximations with a 5% check. Buffer mode uses Henderson-Hasselbalch, and mixing mode uses mole balance over total volume.
When should I use the concentration modes instead of the pH modes?
Use the concentration modes when the task is unit conversion, dilution, mixing, or turning composition data into molarity. Switch to the pH modes only when you need acid-base equilibria such as strong acid/base, weak acid/base, or Henderson-Hasselbalch buffer calculations.
Why do weak-acid and weak-base steps show both exact and approximate values?
The calculator shows the shortcut sqrt(K × C) estimate alongside the exact quadratic result so you can see whether the 5% rule is acceptable for the current concentration and Ka or Kb value.
What should I check before comparing this page with another chemistry calculator?
Check whether both pages use the same concentration units, the same 25 °C water constant assumptions, and the same acid-base model. A mismatch in density, temperature assumptions, or whether the approximation is allowed can change the displayed answer.
How to use concentration and pH modes well
Pick the mode from the chemistry question, not from the unit you started with
Use molarity, percent, dilution, mixing, or w/w → molarity when the job is concentration conversion. Switch to strong-acid, weak-acid, or buffer modes only when the real question is pH, pOH, or Henderson-Hasselbalch behaviour.
Keep units and assumptions aligned
Most mismatches come from mixing grams, millilitres, litres, or percent definitions across sources. Before comparing two answers, check the unit basis, density assumption, and whether the page is using the exact quadratic solution or the weak-acid approximation.
Useful workflow for lab notes or homework
Start with a single target value, confirm the normalized inputs shown in the details panel, then copy the URL or LaTeX after the steps match your notebook. This makes it easier to explain each algebra step instead of only copying the final number.
Common mistakes to avoid
Do not compare buffer pH with strong-acid pH as if they used the same model. Do not reuse a density from one solution in another without checking composition. For weak acids and bases, always read the 5% check before trusting the shortcut estimate.
Recommended next tools
Open titration or buffer pages when you need volume-dependent acid-base curves, or move to reagent and solution-planning tools when the next step is preparing a real solution from the numbers on this page.