Mixture Separation Chemistry Example 2

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Example 2

medium
Describe a step-by-step procedure to separate a mixture of sand, salt, and iron filings. Identify the physical property exploited at each step.

Solution

  1. 1
    Step 1: Use a magnet to remove iron filings (exploits magnetism — iron is magnetic, sand and salt are not).
  2. 2
    Step 2: Add water and stir to dissolve the salt, then filter to remove the sand (exploits solubility — salt dissolves but sand does not).
  3. 3
    Step 3: Evaporate the water from the salt solution to recover solid salt (exploits differences in boiling point — water evaporates at 100°C100°\text{C}, leaving salt behind).

Answer

Magnet → filtration → evaporation (magnetism, solubility, boiling point)\text{Magnet → filtration → evaporation (magnetism, solubility, boiling point)}
Separating a complex mixture often requires multiple techniques applied in sequence, each exploiting a different physical property. The order matters — dissolving the salt before filtering ensures the sand is separated from the salt solution.

About Mixture Separation

Physical methods used to isolate the individual components of a mixture by exploiting differences in their physical properties such as particle size, boiling point, density.

Learn more about Mixture Separation →

More Mixture Separation Examples

Example 1 easy

List four common methods for separating mixtures and give an example of when each would be used.

Example 3 medium

Why can filtration separate sand from water but not salt from water? What technique should be used i

Example 4 hard

Crude oil is a mixture of hydrocarbons with different boiling points. Explain how fractional distill

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