mixtures

• What is a mixture?

  A combination of two or more substances
• What types of substances can be in a mixture?

  Elements and/or compounds
• Can mixtures be easily separated?

  Yes, by physical processes
• What are the physical processes used to separate mixtures?

  • Filtration
  • Evaporation
  • Distillation
  • Chromatography
• What does the separation process depend on?

  The substances being separated
• What do all separation processes rely on?

  A difference of some sort between substances
• How does filtration work?

  Separates insoluble solids from liquids
• What is the method of filtration?

  1. Place filter paper in a funnel.
  2. Pour mixture into the funnel.
  3. Liquid passes through as filtrate.
  4. Insoluble solid remains as residue.
• What is the filtrate in filtration?

  The liquid that passes through the filter
• What is crystallisation used for?

  To separate a dissolved solid from a solution
• How can you test if a solution is saturated?

  Dip a cold glass rod into the solution
• What happens when a saturated solution cools?

  Crystals will form as solubility decreases
• How are crystals collected after crystallisation?

  By filtration
• How are crystals washed after collection?

  With distilled water to remove impurities
• Where can crystals be dried?

  Between filter paper or in a drying oven
• What is simple distillation used for?

  To separate a liquid and soluble solid
• What happens during simple distillation?

  Pure water evaporates and condenses
• What is left behind after simple distillation?

  The solid solute
• What is fractional distillation used for?

  To separate miscible liquids
• How does fractional distillation work?

  Heats to the lowest boiling point first
• What is the boiling point of ethanol?

  78 ºC
• What should be done when the temperature reaches 100 ºC during fractional distillation?

  Stop heating
• What is the process of paper chromatography?

  1. Draw a pencil line on chromatography paper.
  2. Place sample spots on the line.
  3. Lower paper into solvent without submerging the line.
  4. Solvent travels up by capillary action.
  5. Different substances separate based on solubility.
• Why is a pencil used in paper chromatography?

  Ink would run into the chromatogram
• What causes substances to separate in paper chromatography?

  Different solubilities in the solvent
• What happens to substances with higher solubility in chromatography?

  They travel further up the paper
• What does paper chromatography help analyze?

  The composition of inks or dyes