Foundation Level (Fail → Pass)

Basic prompts to establish core understanding.

1. Define the distribution law in simple terms.

2. What is meant by two liquids being immiscible?

3. Give one example of two immiscible solvents.

4. Define solute.

5. What is meant by “partitioning” of a solute?

6. State the condition for the distribution law to apply.

7. What does it mean when a solute is more soluble in one solvent than another?

8. Define distribution ratio.

9. Describe why shaking increases distribution efficiency.

10. Explain what an extraction is.

 Intermediate Level (Pass → Credit)

Prompts requiring explanation, reasoning, and basic calculations.

1. State the mathematical form of Nernst Distribution Law.

2. Explain why solute must not chemically react in either solvent for the law to apply.

3. Describe how multiple extractions improve separation efficiency.

4. Calculate the partition coefficient from given solute concentrations.

5. Explain how temperature affects solute distribution.

6. Describe solute association and its impact on distribution.

7. Describe solute dissociation and its impact on distribution.

8. Give one real-life application of solvent extraction.

9. Explain why pH affects the extraction of weak acids or weak bases.

10. Predict what happens when both solvents are partially miscible.

Advanced Level (Credit → Distinction)

High-order, analytical, and multi-step reasoning prompts.

1. Derive the expression for the amount of solute left after n successive extractions.

2. Analyse how chemical reactions in one solvent cause deviations from the distribution law.

3. Explain the effect of complex formation on solute distribution.

4. Evaluate the influence of ionisation on extraction efficiency.

5. Predict extraction outcomes in multi-solvent systems.

6. Discuss the limitations of the distribution law in systems with strong intermolecular forces.

7. Explain how to optimise extraction using pH adjustments.

8. Calculate solute recovery percentage for multiple extractions.

9. Analyse extraction efficiency in the presence of emulsions.

10. Propose a real-world extraction system and justify solvent choice.