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Difficulty: MediumSeparating Funnel and Solvent Extraction

A mixture of hexane (density =0.66 g/cm3= 0.66\text{ g/cm}^3) and an aqueous sodium chloride solution (density =1.05 g/cm3= 1.05\text{ g/cm}^3) is poured into a separating funnel. After shaking and allowing the mixture to settle into two distinct liquid layers, which of the following statements correctly identifies the bottom layer and the primary principle enabling this separation?

  1. The aqueous sodium chloride solution forms the bottom layer because it is denser and immiscible with hexane.Answer
  2. B
    Hexane forms the bottom layer because it has a lower boiling point than the aqueous sodium chloride solution.
  3. C
    The aqueous sodium chloride solution forms the bottom layer because it has a lower boiling point than hexane.
  4. D
    Hexane forms the bottom layer because it is less dense than the aqueous sodium chloride solution.

Answer

The aqueous sodium chloride solution forms the bottom layer because it is denser and immiscible with hexane.
A separating funnel is used to separate two immiscible liquids based on their density differences. Hexane (a non-polar organic liquid) and an aqueous sodium chloride solution (a polar liquid) do not mix. Since the aqueous solution has a greater density (1.05 g/cm31.05\text{ g/cm}^3) than hexane (0.66 g/cm30.66\text{ g/cm}^3), it sinks to form the lower layer, which can then be drained through the tap.

Step-by-Step Solution

1
Identify the physical properties required for separating funnel extraction.
Separating funnels require two immiscible liquids that separate into distinct phases.
Hexane is a non-polar organic solvent, while water/aqueous solution is polar, making them immiscible.
2
Compare the densities of the two immiscible liquids.
Aqueous NaCl solution (1.05 g/cm31.05\text{ g/cm}^3) is denser than hexane (0.66 g/cm30.66\text{ g/cm}^3).
Gravity causes the liquid with the higher density to sink to the bottom of the funnel.
3
Determine the bottom layer.
The denser aqueous NaCl solution settles at the bottom, while the less dense hexane forms the top layer.
Layer order in a separating funnel is strictly governed by density difference and immiscibility.

Key Concept

Separating Funnel Principles: Immiscibility and Density
Estimated Time:1m 0s
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Topics

Separating Funnel and Solvent Extraction

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