Evaporation separates components in all three processes Steps:

• Identify separation needs: Process 1 removes water from solution; process 2 isolates ethanol from aqueous mixture; process 3 separates nitrogen from liquid air.
• For process 1, heat aqueous copper(II) sulfate to evaporate water, concentrating it for crystallization.
• For process 2, heat fermented glucose mixture to evaporate ethanol, which is then condensed during distillation.
• For process 3, warm liquid air to evaporate nitrogen first due to its lower boiling point (-196°C) in fractional distillation. Why B is correct:
• Evaporation is the phase change from liquid to vapor, enabling solvent removal in process 1 and volatility-based separation in processes 2 and 3. Why the others are wrong:
• A. Crystallisation: Forms solids from solution in process 1 only, not used for liquids in 2 or 3.
• C. Filtration: Separates solids from liquids, irrelevant to vapor-based isolation in any process.
• D. Fractional distillation: Applies to boiling point differences in 2 and 3, but process 1 uses simple evaporation, not fractionation.

Final answer: B