Methods of separating and purifying substances

Explain the distinction between the everyday use of the term 'pure' and its specific definition in chemistry regarding pure substances and mixtures.

Interpret melting point data to distinguish between pure substances, which have sharp melting points, and mixtures, which melt over a temperature range.

Explain which types of mixtures can be separated using specific experimental techniques: simple distillation, fractional distillation, filtration, crystallisation, and paper chromatography.

Describe and select the most appropriate experimental technique to separate a specific mixture based on the properties of its components.

Describe paper chromatography as a separation technique for mixtures of soluble substances, relying on a mobile phase solvent running through a stationary phase paper.

Interpret a paper chromatogram to distinguish between pure and impure substances, identify substances by comparison, and calculate Rf values.

Investigate the composition of inks using simple distillation and paper chromatography techniques.

Describe the processes required to make waste and ground water potable, including sedimentation, filtration, and chlorination.

Describe how sea water can be made potable using distillation.

Understand that water used in chemical analysis must be free from any dissolved salts to ensure accurate results.