In these scenes, the Year 9 Group A chemistry students conducted the laboratory preparation of carbon dioxide gas using two different gas collection methods: over water and downward delivery. The preparation stage included the reaction between a metal carbonate (limestone) and dilute hydrochloric acid, throughout. This reaction produces a salt, water and carbon dioxide. Then they conducted the chemical test for CO2 (colourless limewater turned milky), and also evaluated its properties; e.g. the CO2 evolved extinguished a lighted splint (hence CO2 does not support combustion) and the gas turned green universal indicator solution into an orange/red colour (hence CO2 is acidic in nature).
During this experiment, students also maintained safe laboratory practices and achieved proper experimental skills, scientific writing and record-keeping, as well as the skill of working in a team. Well done to all Year 9 Chemistry students!
Mr. J Borg
Chemistry Teacher