Classifying and separating substances

• A mixture is a matter that contains 2 or more different substances. They can be separated by physical separation techniques
• Non uniform mixtures are called heterogenous mixtures
• Homogenous materials have the same composition throughout the mixture.
• A solution is the only type of homogeneous matter that can be classified as a mixture
• Elements are pure substances that are made of one types of atom. They cannot be broken down
• Compounds are substances that are made up of two or more elements chemically combined.
• Why is every solution a mixture but not every mixture is a solution?

  A solution is a solute dissolved in a solvent, a combination of two different substances. A mixture can be

  a solid, liquid or a gas or a combination of these rather than just a liquid.
• Physical properties are properties that can be determined without changing the chemical composition of a substance
• Chemical properties relate to the ability of a substance to react to form a new substance
• Sieving 


  sieving used the property of particle size to separate a mixture of solids or a mixture of solids and liquids
• Filtration


  uses the difference in particle size and state to separate a mixture on insoluble solid and liquids.

  uses filter paper to trap the sold, called the residue and the the liquid passes through called the filtrate
• Vaporisation


  Is based on the large differences in boiling point of the solute and solvent.

  used to retrieve a solid that has been dissolved in a liquid (solution)
• Simple distillation 


  A technique for separating 2 or more liquids OR separating the liquid from the solid in a solution but also retrieving the liquid component.

  it uses the big difference in boiling points.
• Fractional distillation


  Used to separate liquids that have a significant but small boiling point difference
• Seperating funnel


  Can be used to separate two immiscible (do not mix) liquids. Uses the difference in densities
• Magnetic separation 


  Uses the degree to which a substance is attracted to a magnetic field.

  strongly magnetic materials can be removed from low or non magnetic materials using a low intensity magnetic separator
• Electrostatic separation 


  Separates particles through the difference in electrical charge.

  differently charged particles will be attracted or repelled and follow different paths so they can be caught separately
• Compound


  A pure substance composed of more than one type of atom chemically combined in fixed proportions. Can be broken down chemically but not physically