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Acid-base titration is to determine as precisely as possible the concentration of the acidic solution or a basic solution using a pH measurement.

It is therefore necessary to measure the pH obtained at equivalence. Two methods are commonly used:

- a graphical method suitable for measurements on graph paper: the method of tangents.
- a mathematical method implemented by using a computer: the method of derivation.

**Position** the parallel lines on the curve.

**Click** on the points to display the pH measurement

- To see several examples of acid-base titration.
- To know how to interpret the color change of a color indicator.
- To know how to determine the volume equivalence of an acid-base titration using the method of tangents and the method of derivatives.

pH measurement is easy with a pH meter. However, the accuracy of this instrument is only about 10%! It does not seem suited to the quantitative extent necessary for the determination of unknown…