pH Misturas (aprox)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
This calculator estimates the pH of a mixture of two solutions with different volumes and concentrations of strong acids or bases. It uses the formula -log((C₁V₁ + C₂V₂)/(V₁ + V₂)), where C₁ and C₂ are H⁺ or OH⁻ ion concentrations, and V₁/V₂ are volumes. The formula assumes complete dissociation, valid for strong substances like HCl or NaOH.
Use this tool in labs, industries, or environmental studies to predict the final pH of simple mixtures. For example, diluting hydrochloric acid with water or combining alkaline solutions. Note that the calculation is approximate, it ignores temperature effects, ionic activity, or solute interactions.
If mixing weak acids/bases (e.g., acetic acid), results will be inaccurate since the formula doesn't account for ionization degree. Also, very small volumes or extreme dilutions may cause significant errors. Always validate experimentally in critical cases.
Frequently asked questions
Why is the result called 'approximate'?
The formula ignores real-world effects like ionic activity, temperature, and ion interactions. It's ideal for quick estimates but can't replace experimental testing in critical situations.
Can I use different volumes for each solution?
Yes, the calculator accepts any volume combination as long as units are consistent (ml/L).
Does the formula work for weak bases?
No, since it assumes complete dissociation. For weak bases, the actual pH will be higher than calculated here.
How many solutions can I mix?
This version is limited to two solutions. For more than two, use manual methods or advanced tools.