Separating mixtures

• Pure describes..... 

  Natural substances that have not been processed or changed
• Mixtures are...

  Impure substances
• Just one atom or molecule of something else makes a substance impure
• How to use melting points to determine purity?

  The melting point of a pure substance is single temperatures

  whereas a impure substance:

  • Less than that of a pure substance
  • Range temperature (not just one)
• Pure means...

  A material that is composed of only one type of particle with distant chemical properties
• Formulation means...

  Mixtures where the substances are combined in exact amounts
• what are the three types of chromatography?

  thin layer chromatography, gas chromatography and chromatogram
• what is the mobile phase?

  the solvent that carries the soluble components of the mixture
• what is the stationary phase?

  a fixed absorbent material such as paper
• Name all the famous people involved in creating the model of the atom in order.?

  Dalton - 1803

  Thomson-1897

  Rutherford-1911

  Bohr-1913

  Chadwick-1932
• What are isotopes?


  atoms of an element with the number of protons and electrons staying the same but the number of neutrons changing
• how do you use the melting and the boiling point to determine a substance's purity


  the melting point of a pure substance is a single digit whereas if the substance is impure the melting point would be double didgits but the temperatures would also vary
• what is an alloy?


  A mixture of two or more metals.
• why are alloys stronger than normal metals?

  alloys are stronger because the different sized atoms makes it hard for them to slide against one another
• what is distillation ?

  the process of heating a liquid mixture to the boiling point of one of the solvents and immediately condensing the resulting vapours
• define solvent ?


  a liquid in which chemicals dissolve to make a solution
• define solute


  a substance that is dissolved into a solvent
• define aqueous solution


  a solution where a solute is dissolved in water
• what is a solution?

  a solute dissolved in a solvent