The+Physical+separation+of+substances

= //The methods we can use to separate one substance from another (shown below) are based on differences in physical properties of the substances// = = =

1. __Hand Separation__ - Types of mixtures applied: **mechanical mixtures** of solids - Equipments needed: sieve or magnet - Example: a) Sieves are used to select fine flour particles. b) Magnets are used when we recycle metals. Metal substances can be separated from non-metal substances.

2. __Filtration__ - Types of mixtures applied: **mechanical mixtures** involving liquids and solids - Equipments needed: filter paper, funnel, and beaker - The material which remains on filter paper is called the **residue**, and liquid that passes through filter paper is called the **filtrate**. - Example: Sand can be filtered out from sand-water mixture. In this case, sand is the residue while the water is the filtrate.
 * NOTES:Filtration can work only when the solid particles are not dissolved in the liquid and are large enough to stay on the filter paper; otherwise, the solid particles will pass through the filter paper with the liquid.

3. __Evaporation__ - Types of mixtures applied: solid-in-liquid solution - Equipments needed: evaporating bowl, heat - Example: Evaporating salt solution gives us solid salt.

4. __Distillation__ - Types of mixtures applied: liquid-in-liquid solution (sometimes solid-in-liquid solution) - Equipments needed: distillation setup - The liquid with the lowest boiling temperature evaporates first. - Example: Vinegar can be separated from water using distillation.

5. __Solvent Extraction__ There are two ways of solvent extraction 1) solid from mechanical mixture - Types of mixtures applied: mechanical mixtures of two or more solid particles - Equipments needed: filter paper, funnel, evaporation set, and solvent - In the case that only two types of solid particles are present, choose the solvent that can dissolve only one type, so that the desired solid can be thus separated by filtration or by evaporating the filtrate. - If there are more than two types of solid particles present, repeat the steps to separate every solid particle. - Example: By adding water, salt and flour can be separated. 2) liquid or solid from liquid solution - Types of mixtures applied: liquid solution with liquid or solid - Equipments needed: solvent, separatory funnel - The solvent being chosen should have two properties: a) immiscible with the solvent already present b) dissolve one or more substances from the solution definition >Two liquids are __//miscible//__ if they dissolve each other in all proportions >Two liquids are __//immiscible//__ if they do not mix with each other >Two liquids can be //__partially miscible__// if they are only partially soluble in each other - If there are many different particles dissolved in the solution, repeat the steps to separate every particle.

P.S. There are some more methods of separation, such as recrystallization and gravity separation, but you don’t have to know them for the final exam.

REFERENCE: Hebden Chemistry11, James A. Hebden&Ph.D.,Coordinator of Science Kamloops Secondary Schol,1998 (textbook)