Syllabus Objectives – Separation and Purification

Self Assessment Checklist

Separation and Purification I can do this!
(a) Explain the difference between a pure substance and a mixture.
(b) Explain the difference between a solvent and a solute.
(c) Describe methods of separation and purification for the components of mixtures,
to include:
(i) use of a suitable solvent, filtration and crystallisation or evaporation
to separate and purify mixtures of a solid and a liquid,
(ii) sublimation to separate and purify mixtures of solids,
(iii) distillation to separate and purify a solvent from a solution,
(iv) fractional distillation to separate and purify mixtures of miscible
liquids with different boiling points,
(v) use of a separating funnel to separate and purify mixtures of immiscible liquids,
(vi) paper chromatography to separate two or more components that dissolve in
the same solvent.
(d) Suggest suitable separation and purification methods, given information
about the substances involved in the following types of mixtures:
(i) solid-solid,
(ii) solid-liquid,
(iii) liquid-liquid (miscible and immiscible).
(e) Describe paper chromatography and interpret chromatograms including
comparison with ‘known’ samples and the use of Rf values.
(f) Explain the need to use locating agents in the chromatography of
colourless compounds (knowledge of specific locating agent is not required).
(g) Deduce from the given melting point and boiling point the identities of
substances and their purity.
(h) Explain that the measurement of purity in substances used in everyday
life, e.g. foodstuffs and drugs, is important.