The most suitable process of obtaining water from an aqueous solution of sugar i

Analyze the question: You have sugar dissolved in water (an aqueous solution). The goal is to get the water out of it, not the sugar.

Concept: Sugar dissolves completely in water, so it forms a homogeneous mixture. Different separation methods suit different mixtures:

• Crystallization: recovers the dissolved solid (sugar) by evaporating part of the solvent. The water is lost as vapour, not collected.
• Distillation: heats the solution so the water boils off as vapour. The vapour is then cooled in a condenser and collected as pure liquid water. The sugar stays behind in the flask because it has a very high boiling point.
• Filtration: separates an insoluble solid from a liquid. Dissolved sugar passes through filter paper, so this fails.
• Decantation: pours off a liquid from a settled insoluble solid. It does not work for dissolved substances.

Solution:

1. Sugar solution → heat in a distillation flask.
2. Water (boiling point 100 °C) vaporizes; sugar does not.
3. Vapour passes through a condenser (cooled by running water) and turns back into liquid.
4. Pure water collects in the receiver (the distillate), and sugar remains in the flask.

Answer: Distillation, which is option B.

Tip: Remember the pairing:

• Want the solvent (water) from a solution → Distillation
• Want the dissolved solid → Crystallization/Evaporation
• Insoluble solid in liquid → Filtration/Decantation

Keep practicing these separation techniques; they appear often in WASSCE, NECO and JAMB!