Question

Oil is extracted from rice bran by solvent extraction method. In this method, usually, n-hexane is used. The boiling point of n-hexane is:

• A. $60^\circ$C -- $64^\circ$C
• B. $65^\circ$C -- $70^\circ$C
• C. $71^\circ$C -- $75^\circ$C
• D. $76^\circ$C -- $80^\circ$C

Hint:

n-Hexane boils around 68°C. Always remember: low boiling point = easy solvent recovery.

Answer 1

The Correct Option is B

Concept: n-Hexane is a commonly used solvent in oil extraction processes due to its suitable boiling point, non-polar nature, and high efficiency in dissolving oils. Its boiling point is an important parameter because it determines ease of solvent recovery through evaporation.

Step 1: Understanding solvent extraction.
In solvent extraction:
• Oil-bearing material is treated with a solvent (n-hexane)
• Oil dissolves in the solvent forming a miscella
• The solvent is later removed by heating (distillation)

Step 2: Importance of boiling point.
The solvent should have:
• Low boiling point (easy evaporation)
• High solvency for oil
• Safe handling characteristics

Step 3: Boiling point of n-hexane.
The standard boiling point of n-hexane is approximately: \[ 68^\circ C \] This falls within the range $65^\circ$C to $70^\circ$C.

Step 4: Evaluating options.
• $60^\circ$C -- $64^\circ$C — Slightly lower than actual value.
• $65^\circ$C -- $70^\circ$C — Correct range including 68°C.
• $71^\circ$C -- $75^\circ$C — Higher than actual value.
• $76^\circ$C -- $80^\circ$C — Much higher, incorrect.

Step 5: Final reasoning.
Since the actual boiling point lies around 68°C, the closest correct range is $65^\circ$C to $70^\circ$C. Final Conclusion:
The boiling point of n-hexane lies in the range $65^\circ$C -- $70^\circ$C. Hence, the correct answer is option (2).