Acids, bases and indicators – titration drop by drop

Integrated ScienceChemical ReactionsAges 13–14

A beaker holds an acid or base solution with an indicator already added (litmus, phenolphthalein, or universal pH paper). Students add HCl or NaOH one mL at a time from two burettes (button or tap on the beaker), watch the indicator change color, the pH scale needle move, and the pH-vs-volume curve grow. The amounts of H⁺ and OH⁻ and the neutralization equation update continuously so students can pinpoint the neutralization point.