Mixture Separation Chemistry Example 3

Follow the full solution, then compare it with the other examples linked below.

Example 3

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

Solution

  1. 1
    Sand particles are insoluble and large enough to be trapped by filter paper, while dissolved salt exists as individual Na+\text{Na}^+ and Clāˆ’\text{Cl}^- ions that are far too small to be caught by filter pores.
  2. 2
    To separate salt from water, use evaporation or distillation ā€” heating drives off the water while the salt remains behind.

Answer

SaltĀ ionsĀ passĀ throughĀ filters;Ā useĀ evaporationĀ instead.\text{Salt ions pass through filters; use evaporation instead.}
Filtration depends on particle size ā€” it only works for particles larger than the pore size of the filter. Dissolved substances exist at the molecular/ionic level and require techniques based on other properties like boiling point.

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 ā†’

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 2 medium

Describe a step-by-step procedure to separate a mixture of sand, salt, and iron filings. Identify th

Example 4 hard

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

ā† All Mixture Separation Examples Mixture Separation Concept