← Overview VMBOStep 2 of 3

Separation methods

Syllabus VMBO: Product investigation

Question 1 / 50 correct

Which method removes undissolved sand from salt water?

Choose your answer
More explanation and a worked example

Start with the desired product

A filter retains undissolved solid particles. Dissolved salt passes through an ordinary filter with the water. During evaporation the solvent leaves as vapour; it is not automatically collected.

Properties make the difference

Distillation uses differences in volatility and collects vapour after cooling. Extraction uses differences in solubility. Adsorption binds substances to a surface. Settling uses particles sinking under suitable conditions.

You have sand, dissolved salt and water. You want to recover dry salt.

  1. Filter: sand remains as residue, while salt solution passes through as filtrate.
  2. Evaporate the filtrate to recover the salt.
Want to collect water as well? Choose distillation after filtration.
Sources for this topic