MODEL RELEASED. Titration experiment. Student adding an alkaline solution from a burette to a solution of citric acid. The indicator used here (phenolphthalein), goes pink in alkaline solutions, and is colourless in acidic solutions. When the pink colour remains and cannot be swirled away, the acid has been neutralised. The measured alkali volume (measured with the burette) will be then be compared to the known volume of acid, giving information on reaction chemistry and chemical concentrations. This analytical technique is known as titration.