calcium carbonate experiment
Answers
Calcium carbonate is strongly heated until it undergoes thermal decomposition to form calcium oxide and carbon dioxide. The calcium oxide (unslaked lime) is dissolved in water to form calcium hydroxide (limewater). Bubbling carbon dioxide through this forms a milky suspension of calcium carbonate
This experiment can be carried out conveniently in groups of two or three and takes about 40–45 minutes.
Equipment
Apparatus
Eye protection
Tripod
Gauze
Bunsen burner
Tongs
Boiling tubes, x2 (note 1)
Drinking straw (note 2)
Dropping pipette
Filter funnel, small
Filter paper
Apparatus notes
Use large (150 x 25 mm) test tubes (boiling tubes).
Freshly purchased drinking straws should be used and each student issued with their own straw.
Chemicals
Calcium carbonate
Universal Indicator solution (HIGHLY FLAMMABLE)
Health, safety and technical notes
Read our standard health and safety guidance.
Wear eye protection.
Calcium carbonate, CaCO3(s) – see CLEAPSS Hazcard HC019b. The calcium carbonate used should be in the form of pea sized lumps of chalk. Blackboard chalk should not be used as it is likely to be mostly calcium sulfate.
Universal indicator solution (HIGHLY FLAMMABLE) – see CLEAPSS Hazcard HC032 and CLEAPSS Recipe Book RB047.
