Chapter 4 : Separation techniques

• Distillation

  How it works: Boiling water to make steam, then cooling it back into water.

  • Uses: Making clean water from dirty water, making alcohol.
• Evaporation to Dryness

  How it works: Letting water disappear and leaving behind solid stuff like salt.

  • Uses: Getting salt from seawater, making sugar from sugary water.
• Filtration

  How it works: Passing dirty water through a special filter that catches the dirty bits.

  • Uses: Cleaning dirty water, separating sand from water.
• Chromatography

  How it works: Letting colors in a mixture spread out on a special paper.

  • Uses: Finding out what colors are in markers, separating colors in ink.
• Magnetic Attraction

  How it works: Using a magnet to pull out certain things from a mix.

  • Uses: Sorting metal from non-metal, finding tiny metal bits in sand.
• Reverse Osmosis

  How it works: Pushing water through a very tiny hole to take out the bad stuff.

  • Uses: Making seawater into drinking water, cleaning really dirty water.
• Distillation

  1. Boil liquid to make steam

  2. Cool steam back into liquid
• Uses of distillation

  • Making clean water from dirty water
  • Purifying alcohol
• Evaporation to dryness

  1. Let water evaporate

  2. Leaves behind solid substances
• Substances obtained by evaporation to dryness

  • Salt from seawater
• Filtration

  1. Separate solid particles from liquid or gas

  2. Pass through filter that catches solid particles
• Uses of filtration

  • Cleaning dirty water
  • Separating sand from water
• Chromatography

  1. Colors in mixture spread out on special paper

  2. Shows different substances
• What chromatography can help find out

  • Colors in markers
  • Separate colors in ink
• Magnetic attraction

  Uses magnet to pull out certain materials from mixture based on magnetic properties
• Applications of magnetic attraction

  • Sorting metal from non-metal
  • Finding tiny metal bits in sand
• Reverse osmosis

  1. Push water through tiny hole to remove impurities

  2. Leaves clean water
• Purpose of reverse osmosis

  • Make seawater into drinking water
  • Clean very dirty water
• Making clean water using distillation

  1. Boil dirty water to make steam

  2. Cool steam back into water
• Substances separated by filtration

  • Sand from water
• Main methods of chromatography

  • Paper chromatography
• Obtaining salt by evaporation to dryness

  1. Let seawater evaporate

  2. Leaves salt behind as solid crystals
• Simple distillation vs fractional distillation

  • Simple distillation separates liquids with very different boiling points
  • Fractional distillation separates liquids with closer boiling points
• How reverse osmosis cleans water

  1. Push water through membrane that blocks impurities

  2. Leaves clean water on other side
• Why magnetic attraction is useful for separating materials

  Can easily separate materials based on magnetic properties, like sorting metal from non-metal
• Mixtures separated by chromatography

  • Ink into different color components