MODEL RELEASED. Titration. Schoolgirl adding an alkaline solution (from a burette) to a known volume of acid (in flask). The alkaline solution will neutralise the acid. The acidity is measured by a digital pH meter (lower left). The burette is graduated to show volumes, allowing the volume of the alkaline solution added to neutralise the acid to be measured. The volume of alkali is compared to the known volume of acid, giving information on reaction chemistry and chemical concentrations.