Mixtures & chromatography,separation techniques,distillation

• How are mixtures different from compounds?

  Mixtures do not have chemical bonds between their components.
• What methods can be used to separate the parts of a mixture?

  Filtration, crystallisation, simple distillation, fractional distillation, and chromatography.
• What is air primarily composed of?

  Air is a mixture of gases, mainly nitrogen, oxygen, carbon dioxide, and argon.
• What is crude oil a mixture of?

  Crude oil is a mixture of different length hydrocarbon molecules.
• How do the properties of a mixture relate to its components?

  The properties of a mixture are just a combination of the properties of its separate parts.
• What happens when you mix iron powder and sulfur?

  The mixture will show the properties of both iron and sulfur.
• What is the process of paper chromatography?

  1. Draw a line near the bottom of filter paper with pencil.
  2. Add a spot of ink to the line.
  3. Place the paper in a beaker of solvent.
  4. Ensure the ink does not touch the solvent.
  5. Cover the container to prevent evaporation.
  6. The solvent moves up the paper, carrying the ink.
  7. Different dyes move at different rates, forming spots.
  8. Insoluble dyes remain on the paper.
  9. The result is a chromatogram with a solvent front.
• What is the purpose of using a pencil to draw the line in chromatography?

  Pencil marks are soluble and won't dissolve in the solvent.
• What is the role of the solvent in chromatography?

  The solvent carries the ink up the paper, separating the dyes.
• What is the end result of a chromatography experiment called?

  The end result is called a chromatogram.
• What are the methods of separating mixtures mentioned in the study material?

  • Filtration: separates insoluble solids from liquids.
  • Crystallisation: separates soluble solids from solutions.
  • Evaporation: quickly separates soluble salts from solutions.
  • Simple distillation: separates liquids from solutions.
  • Fractional distillation: separates mixtures of liquids with different boiling points.
• What is filtration used for?

  Filtration is used to separate insoluble solids from liquids.
• What is the first step in the evaporation process?

  Pour the solution into an evaporating dish.
• What is the main difference between evaporation and crystallisation?

  Evaporation is quicker but can decompose salts, while crystallisation is slower and forms pure crystals.
• How do you separate rock salt into its components?

  Grind the mixture, dissolve in water, filter out sand, and evaporate the water to get salt crystals.
• What is simple distillation used for?

  Simple distillation is used to separate a liquid from a solution.
• What happens during simple distillation?

  The part of the solution with the lowest boiling point evaporates first.
• What is the limitation of simple distillation?

  It can only separate substances with very different boiling points.
• What is fractional distillation and when is it used?

  • Fractional distillation separates mixtures of liquids.
  • It uses a fractionating column to allow liquids to evaporate at different temperatures.
  • It is used when liquids have similar boiling points.
• What is the first step in fractional distillation?

  Put the mixture in a flask and attach a fractionating column on top.
• How does the fractionating column work in fractional distillation?

  The column is cooler at the top, allowing higher boiling liquids to condense and return to the flask.
• What happens when the temperature on the thermometer matches the boiling point of a liquid in fractional distillation?


  The liquid with that boiling point will reach the top of the column and be collected.
• What is the purpose of distillation in chemistry?

  Distillation is used to separate mixtures that contain liquids.
• What is the main difference between simple and fractional distillation?

  Simple distillation is for separating one liquid from a solution, while fractional distillation is for separating multiple liquids with similar boiling points.
• What are the applications of chromatography in real life?

  • Testing urine samples for performance-enhancing drugs.
  • Solving mysteries at crime scenes.
  • Analyzing substances using the Periodic Table.