Points for SAC 1 Unit 3 2013 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. What are the roles of the stationary phase and mobile phase in each chromatography technique. List the s. phase and m.phase in TLC, GC and HPLC What does adsorbing and desorbing mean? What differs a qualitative analysis from a quantitative analysis? Why should you not let the solvent from reach the end of the paper in TLC? What is an analyte? What does a chromatogram show you? Why can the retention factor not be greater than 1? What is the relationship between adsorption and Rf/Rt? What is HPLC used to analyse? What is an eluent? Eluate? How do you determine the concentration of an unknown using a calibration graph? Why do you dilute samples? Why does the solvent need to be below the origin? What are the main differences between HPLC and GC? Why is the column in HPLC packed with very fine particles? What does peak area tell you? Can you calculate % by mass and concentration? Can you read from a calibration graph? Can you do dilutions? What is a stock solution? What is the difference between Rt and Rf? How can you calculate concentration if you don’t have a FULL set of standards? What type of a substance is HPLC used to analyse? What type of a substance is GC used to analyse? What influences separation in chromatography? 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. What is the beer lambert law? What part of the electromagnetic spectrum is used for UV-VIS/AAS? What is the oven used for in GC? Describe what happens at a molecular level what atoms absorb light. What is the purpose of the monochromator? Which techniques are qualitative/which are quantitative? What type of a substance is AAS used to analyse? What type of a substance is UV-VIS used to analyse? Which is the most sensitive technique? Why is pulsed light used in AAS? How is a suitable wavelength selected in UV-VIS? Define atomisation and vaporisation What is the role of the flame in AAS? What is the relationship between concentration and absorption? What is the purpose of a HCL in AAS? What is the purpose of a reference cell in UV-VIS? Why does the intensity of the light change as it passes through the sample? Do you know how to convert between %(w/w) %(w/v) %(v/v) ppm, g/L etc?