Copper carbonate, an insoluble solid, is mixed with sodium chloride, a soluble solid. The mixture is added to water, stirred, and then filtered.
1. What substance is left on the filter paper?
2. The other substance is present in the filtrate. How can a solid sample of this substance be obtained?
Answers
Answer:
In this experiment the soluble salts are magnesium sulfate and sodium carbonate, and the insoluble salt formed is magnesium carbonate, which can be filtered, dried and collected.
This is a short standard class experiment. It should take no more than 20 minutes to the point at which the wet product can be set aside to dry.
If the solutions can be provided in pre-measured 25 cm3 quantities in labelled containers, distribution of chemicals and control of quantities can be easily managed, and the practical work can begin without delay.
Sodium carbonate in dilute solution is weakly alkaline. So the few other safety issues are essentially restricted to safe handling of glassware. Even these can be minimised by the use of polythene filter funnels. This experiment is therefore suitable as a class experiment for most classes.