Question 83
Neutralisation method: put dilute hydrochloric acid in a burette; measure 20 cm³ sodium hydroxide into a small flask and add a few drops of universal indicator. Add acid slowly, swirling, until green. Add a spatula of charcoal and stir to remove the indicator colour. Filter, warm the filtrate gently in an evaporating basin until crystals start at the edge, then leave for days to evaporate slowly. Answer equipment and risk questions before doing the practical; hot liquid can spit and burn. What colour is universal indicator in a neutral solution?
