1. Separation Techniques

2. Hand separation Filtration Extraction Fractional distillation Chromatography Centrifugation Evaporation Distillation Solvent extraction Recrystallization Gravity separation

3. Separation Techniques Which types of matter can we separate? Why?

4. Filtration Separates liquid-solid mixtures Filter paper: lets liquid through, keeps solids out Vacuum filtration: water flow creates vacuum in filter flask and sucks air through the filter paper

5. Filter Paper

6. Vacuum Filtration

7. Chromatography Separates liquid-liquid mixtures A mixture carried by a solvent through a stationary medium (solid column, filter paper) Separation occurs when components of the mixture move through the medium at different speeds

8. Paper & Thin Layer Chromatography Solvent can be a number of things (H 2 O, ether, ethyl acetate) Stationary medium: chromatography paper

9. Paper & Thin Layer Chromatography “Spot” your chromatography paper with your mixture near the bottom Put your paper in the container with solvent Solvent will go up the paper and carry the mixture up with it Components will separate if they travel at different speeds

10. Paper & Thin Layer Chromatography

11. To identify the components of a mixture, use Rf values Rf = distance traveled by component distance traveled by the solvent Compare experimental Rf values with reference Rf values to identify your components

12. Evaporation Separates solid-liquid mixtures Boil away liquid to leave the solid E.g. salt production: evaporate water from seawater to get salt Can this method be used for liquid-liquid mixtures?

13. Evaporation of Sea Water

15. Distillation Separates liquid-liquid mixtures Uses different boiling points of liquids When would this method not be useful?

16. Distillation Liquid with the lowest boiling point evaporates 1 st Gas is cooled and collected elsewhere Once all of the 1 st liquid is collected, repeat for the liquid with the next lowest boiling point

17. Distillation