Specification Point 2.39:
Describe an experiment to prepare a pure, dry sample of a soluble salt, starting from an insoluble reactant
Preparation of Soluble Salts
Using Dilute Acid and Insoluble Base:
The filtration of the mixture to remove the excess base
- Add dilute acid into a beaker and heat using a bunsen burner flame
- Add the insoluble base, a little at a time, to the warm dilute acid and stir until the base is in excess (i.e. until the base stops disappearing and a suspension of the base forms in the acid)
- Filter the mixture into an evaporating basin to remove the excess base
- Heat the solution to evaporate water and to make the solution saturated. Check the solution is saturated by dipping a cold, glass rod to the solution and seeing if crystals form on the end.
- Leave the filtrate in a warm place to dry and crystallise
- Decant excess solution
- Blot crystals dry
Aiming for a Level 9?
See if you’ve got what it takes. Test yourself with our topic questions.
Jamie got a First class degree in Chemistry from Oxford University before going on to teach chemistry full time as a professional tutor. He’s put together these handy revision notes to match the Edexcel IGCSE Chemistry specification so you can learn exactly what you need to know for your exams.
More Edexcel IGCSE (9-1) Chemistry Revision Resources