Chemistry / Science GCSE: Prepare a pure, dry sample of a soluble salt from an insoluble oxide
This video demonstrates the GCSE Chemistry and Combined Science required practical to prepare a pure, dry sample of a soluble salt from an insoluble oxide, included in AQA, Edexcel and OCR specifications.
This video uses the example of the extraction of copper sulfate crystals from copper oxide and dilute sulfuric acid. The video highlights the three distinct steps in the method, explaining the purpose and specific safety precautions needed at each step.
The practical allows development of Apparatus & Techniques Chemistry 2, 4 and 6 (DfE GCSE subject content guidance, Appendix 4).
This video could be used before or after students carry out their own practical to prepare a dry soluble salt from an insoluble oxide or carbonate.
If used beforehand, the video could reinforce some of the science theory behind separating mixtures.
If used after the practical has been carried out, the video could be used to revisit and reinforce the three distinct steps and the purpose of each step.
The video also allows a focus on the specific safety precautions needed at each step, highlighting the need to explain the purpose of any safety precaution.
Points for discussion:
Students sometimes struggle to recognise or recall the distinct steps used in preparing a dry, soluble salt from an insoluble oxide or carbonate using dilute acid.
This video separates, describes and explains each of three steps that are always required in the process.
If they can identify and explain each of these steps for their own practical, they should then be able to apply the learning to preparing other salts, using different reactant oxide or carbonate and different dilute acid.
Students also often find it challenging to identify specific safety precautions. This video highlights the safety precautions needed at each step and stresses the purpose of each precaution.
Students should practise writing equations to show how a variety of soluble salts can be prepared from different reactants (insoluble oxides or carbonates and dilute acids).
If possible, allow students to carry out the process to produce more than one salt to reinforce the fact that the same three steps are required each time.
Suitable for teaching Chemistry and Combined Science at Key Stage 4 and GCSE in England, Wales and Northern Ireland, and at National 4 and 5 in Scotland.