Singapore SEC G3 Chemistry free practice questions with answers

Correct answer: C — Dissolving in water, filtering and evaporating the filtrate

• The method must use a difference in properties of the substances: salt dissolves in water but sand does not.
• The most suitable method is dissolving in water, filtering and evaporating the filtrate.
• Why the other options are wrong:
• A (Simple evaporation to dryness): simple evaporation to dryness is not suitable for this mixture: it relies on a different property
• B (Paper chromatography): paper chromatography is not suitable for this mixture: it relies on a different property
• D (Using a separating funnel): using a separating funnel is not suitable for this mixture: it relies on a different property

Choose the separation method from the physical properties (solubility, boiling point, state) of the components.