Chemical Analysis

• Pure substance


  Single element or compound not mixed with any other substance
• Mixtures are not chemically combined
• Sublimation is the change of state directly from a solid to a gas
• melting is changing from a solid to a liquid
• freezing is changing from a liquid to a solid
• boiling is changing from a liquid to a gas
• condensing is changing from a gas to a liquid
• melting point is the temperature at which a solid turns into a liquid.
• boiling point is the temp at which a liquid turns into a gas.
• pure substances have specific, sharp and well defined melt and boil points
• during a change of state, temperature doesn't change until all bonds have been broken.
• Impure substances melt and boil over a range of temperatures
• A formulation is a mixture of different substances in measured quantities to make a useful product
• formulations

  alloys, medicines, fertiliser
• a mixture is two or more substances mixed together
• a solute is the substance that dissolves in a solvent (sugar)
• a solvent is the liquid in which a solute dissolves (water)
• a solution is a solute dissolved in a solvent (sugar solution)
• a soluble substance is one that will dissolve in a solvent
• an insoluble substance is one that does not dissolve in a solvent
• filtration

  separates an insoluble solid from a liquid
• filtration

  A) residue

  B) filter paper

  C) filter funnel

  D) filtrate

  
• crystallisation

  seperates a solute from a saturated solution
• crystallisation

  A) solvent vapour

  B) evaporating basin

  C) solution

  D) wire gauze

  E) heat

  
• simple distillation 


  seperates a solvent from a solution
• simple distillation

  A) heat

  B) anti bumping granules

  C) thermometer

  D) cold water out

  E) liebig condenser

  F) solution

  G) cold water in

  H) distillation

  
• fractional distillation

  separate a mixture of miscible liquids providing they have different boiling points
• fractional distillation

  A) heat

  B) distillation flask

  C) fractionating column

  D) thermometer

  E) water out

  F) water in

  G) liebig condenser

  H) reciever

  I) pure liquid

  
• miscible liquids mix together
• immiscible liquids do not mix together and instead form two layers
• chromatography

  solvent is the mobile phase
• chromatography

  paper is the stationary phase
• chromatography is used to separate mixtures of soluble coloured compounds
• solvent front is the furthest distance travelled by the solvent
• Rf value

  distance moved by the substance / distanced moved by the solvent
• in chromatography the most soluble solute will travel the farthest up the paper
• water turns white anhydrous copper (II) sulfate blue
• cations can be identified with a flame test
• lithium

  crimson
• sodium

  yellow/orange