Cambridge O Level Chemistry · Syllabus 5070 · Experimental Techniques and Chemical Analysis
Separation Technique
What is Separation Technique?
A physical method that separates the components of a mixture by exploiting a difference in their physical properties. The Cambridge O Level Chemistry syllabus names five: using a suitable solvent, filtration, crystallisation, simple distillation and fractional distillation. The technique is chosen from the property information given about the substances involved, and the choice is justified by naming that property difference.
This definition is part of the Experimental Techniques and Chemical Analysis chapter in Cambridge O Level Chemistry.
Questions students ask about Separation Technique
How should you choose a separation technique on an unfamiliar substance?
Match the technique to the property difference the question gives you: use a suitable solvent or filtration when solubility differs, crystallisation to recover a dissolved solid, simple distillation to separate a solvent from a dissolved solid or non-volatile component, and fractional distillation when two or more miscible liquids have different boiling points. A full-credit answer names the method, states the property difference that makes it work, and says what is kept.