Separating Mixtures Preparation for Lab Experiment

Mixtures are Physical Blends  Composition of the components was not changed  Components can be separated by Physical means  Elements and compounds will not be chemically changed

Frequently Used Ways to Separate Mixtures  Straining (filtering)  Using a magnet  Evaporation  Dissolving  Physical separation

Filtering or Straining to Separate Mixtures  Principle: separate matter by particle size  Use a filter or strainer  Particles smaller than holes pass through  Particles larger than holes stay on strainer  Examples:  Filter paper  small holes  used for making coffee & tea  Colander  to separate water & pasta

Using a Magnet to Separate Mixtures  Principle: separate matter by magnetism, a physical property  Most materials are NOT attracted to magnets  Iron - most common ferro-magnetic material  Example: magnets are used to separate recycled metals from each other  steel is attracted to magnets  aluminum is not

Evaporation to Separate Mixtures  Principle: separate matter by allowing the solvent to become a gas, leaving the solute(s) behind  Filtering a solution will not separate solutes that are totally dissolved  Filtering will not separate particles from colloids  Many solvents will evaporate at room temperature  heating - speed up the process  The composition of the solute(s) is the same as before being dissolved  Example: People get salt from sea water by letting the water evaporate

Dissolving to Separate Mixtures  Principle: separate matter by dissolving the soluble part(s) of a mixture, leaving the insoluble part(s) behind.  Soluble pieces dissolve leaving behind the insoluble components  Dissolving typically happens during filtration  Example: Recycling paper uses water to remove binders, etc. from paper fibers.

 Visually identify  Separate by hand or other mechanical means  Example: MCHS recycling bins Physical Separation

Complicated Mixtures Can be separated by using more than one techniqueCan be separated by using more than one technique Separated portions can often be separated furtherSeparated portions can often be separated further Sequence of separations is dependent on the nature of the mixtureSequence of separations is dependent on the nature of the mixture

How Would You Separate: Salty water?Salty water? Salt and iron filings?Salt and iron filings? Gravel, sand, and sugar?Gravel, sand, and sugar? Gravel, sand, sugar, and iron filings?Gravel, sand, sugar, and iron filings?

Experimental Design Component Name Physical Properties SaltDissolves in water, White crystals Sand Small grains, many colors, does not dissolve in water IronMetallic, small filings Pebbles/GravelLarger rock piece, dark gray Copper (II) Sulfate Dissolves in water, Blue when dissolves How would you separate a mixture containing all of the following components?