Separating Substances

Separating Substances

1. Something is a MIXTURE if it contains two (or more) substances that are not chemically joined together.The substances in a mixture can often be easily separated from one another.

2. A PURE substance only contains one material and so cannot be separated in any way (unless a chemical reaction takes place)

3. Filtration is a common method of separating an insoluble solid from a liquid. An example of such a mixture is sand and water. Filtration is used in water treatment plants, where water from rivers are filtered to remove solid particles.

4. Paper Chromatography is often used in the food industry. It is used to identify chemicals (coloring agents) in foods or inks. For example, if a scientist wants to know how many substances are in a particular blob of ink, paper chromatography can be used.

5. Evaporation is great for separating a mixture (solution) of a soluble solid and a solvent. The process involves heating the solution until the solvent evaporates (turns into gas) leaving behind the solid residue.

6. Simple Distillation is best for separating a liquid from a solution. In a way, the concept is similar to evaporation, but in this case, the vapor is collected by condensation. For example, if you want to separate water from a salt solution, simple distillation would be great for this.

   • Fractional distillation is best for separating a solution of two miscible liquids.Fractional method takes advantage of the different boiling points of the two liquids.

7. Magnetism is ideal for separating mixtures of two solids with one part having magnetic properties. Some metals like iron, nickel and cobalt have magnetic properties whiles gold, silver and aluminum do not. Magnetic elements are attracted to a magnet.

8. Separating funnel is when two liquids that do not dissolve very well in each other (immiscible liquids) can be separated by taking advantage of their unequal density. A mixture of oil and water, for example, can be separated by this technique.