Mind Map C2

Mind Map C2

1. Paper chromatography

   • A small concentrated spot of solution that contains the sample is applied to a strip of chromatography paper about two centimeters away from the bottom edge of the paper
   • This sample is absorbed onto the paper. The paper is then dipped into a suitable solvent, such as ethanol or water, taking care that the spot is above the surface of the solvent, and placed in a sealed container.
   • The solvent moves up the paper by capillary action, which occurs as a result of the attraction of the solvent molecules to the paper. As the solvent rises through the paper it meets and dissolves the sample mixture, which then travels up the paper with the solvent solute sample

2. Filtration

   • Gravity filtration is the method of choice to remove solid impurities from a liquid

3. Crystallisation

   • A solid which has dissolved in a liquid can be separated by crystallisation. If the solution is concentrated and the cooled, crystallisation will take place. Impurities will remain behind in the solution

4. Distillation

   • Process of heating a liquid until it boils, capturing and cooling the resultant hot vapors, and collecting the condensed vapors. Used to separate a liquid from dissolved substances

5. Fractional Distillation

   • Mixtures of liquids can be separated by fractional distillation. Crude oil is separated into its components by fractional distillation

6. Oil refinery

   • Industrial process plant where crude oil is processed and refined into more useful petroleum products.

7. Food purity

   • For most foods, we monitor and control the presence of any harmful chemicals. Legislation defines the permissible level of substances allowed in food. They include pesticides, medicines, and chemicals used in the production of food

8. Determining purity

   • The melting and boiling points of solids and liquids are good indicators of purity unless the substance decomposes. Melting and boiling points are accurately known for a large number of substances. If a solid is impure then the melting point is lowered. If a liquid is impure then the boiling point is elevated