Chemistry - States of Matter

• The properties of a solid are:

  • Low kinetic energy
  • Particles have fixed positions but are vibrating
  • Strong forces of attraction between particles
  • Easy to squash
  • Fixed shape
  • Do not flow
  • High density
• The properties of a gas are:

  • Highest kinetic energy
  • Particles freely move
  • Small forces of vibration
  • Difficult to squash
  • No fixed volume
  • Flow easily
  • Low density
• The properties of a liquid are:

  • Difficult to squash
  • No fixed volume
  • Flow easily
  • Low density
• Evaporation can happen at any temperature and only occurs at the surface of the substance. It happens when the particles get enough kinetic energy to leave the liquid. No additional heat source is needed to do this.

  It is slow.

  It cools the remaining liquid.
• Boiling is when a whole substance reaches the temperature at which it turns from a liquid to a gas and rapidly forms bubbles that are escaping the liquid.

  An external source causes it and the substance is raised in temperature.
• A pure substance is a single substance with a fixed composition that does not have anything else mixed with it.
• An impure substance/mixture contains two or more different substances that are not chemically joined.
• A pure substance has a sharp melting point.
• An impure substance/mixture melts over a range of temperatures.
• A solute is a substance that dissolves in a liquid to form a solution.
• A soluble has the capacity to dissolve in a solvent.
• A solvent is a liquid in which the substance dissolves to make a solution.
• An insoluble does not have the capability to dissolve in a solvent.
• A solution is formed when a substance dissolves in liquid.
• Chromatography separates solutions that contain multiple soluble solutes. They are separated because they have different solubilities within that particular solvent.
• We can calculate an Rf value of dye in a chromatogram.

  Rf = distance moved by a spot/distance travelled by solvent.

  The closer the Rf value to 1, the more soluble the substance is.
• What does paper chromatography allow us to do?


  Allows us to separate substances based on their different solubility.
• What is solubility?

  The amount of given substance that can be dissolved in a certain amount of solvent.
• What is a solvent?

  The liquid in which the solute dissolves to form a solution.
• What is the stationary phase?

  This is the paper because it doesn't move.
• What is the mobile phase?

  This is the solvent as it is moving.
• What is a pure substance?

  A substance that only consists of only one element or compound.
• Why should the starting line be drawn in pencils?

  If the line is drawn in ink the line moves up the paper with the solvents.
• What can the Rf value be used to figure out

  Rf value can be used to identify unknown chemicals if they can be compared to a range of referenced substances.