Decolorization

CHEMISTRY

1. DEcOLORIZATION Experiment #5 CHEM 3 (Organic Chemistry) Group 6:

2. Objective: At the end of this experiment, the student shall have: Purified an organic compound Compared the effectiveness of heating and the addition of color –absorbing reagents to purify the compound

3. Materials: Bunsen burner

4. Materials: Tripod

5. Materials: Wire gauze

6. Materials: Test tube rack & 3 test tubes

7. Materials: Spatula

8. Materials: Test tube brush

9. Materials: 2 250ml beaker

10. Materials: Filter paper

11. Materials: Graduated cylinder

12. Materials: clay triangle

13. Materials: iron stand

14. Materials: glass funnel

15. Materials: pipette

16. Materials: aspirator

17. Materials: stirring rod

18. Materials: platform balance

19. Materials: watch glass

20. Chemicals (REAGENTs) : brown sugar

21. Chemicals (REAGENTs) : activated carbon

22. Chemicals (REAGENTs) : distilled water

23. pRocedure 1 50ml H2O 5g brown sugar

24. pRocedure 1 brown sugar solution

25. pRocedure 2

26. pRocedure 2 2ml brown sugar sol’n test tube 1

27. pRocedure 2 2ml brown sugar sol’n (for control) test tube 1

28. pRocedure 2 2ml brown sugar sol’n (for control) note the color of the solution. test tube 1

29. pRocedure 3 brown sugar sol’n + heat

30. pRocedure 2

31. pRocedure 3 brown sugar sol’n + heat 0.1 g activated carbon

32. pRocedure 3 brown sugar sol’n + heat

33. pRocedure 4 test tube 2

34. pRocedure 4 2 ml brown sugar sol’n with activated carbon test tube 2

35. pRocedure 4 2 ml brown sugar sol’n with activated carbon test tube 2

36. pRocedure 4 2 ml brown sugar sol’n with activated carbon test tube 2 note the color of the solution.

37. pRocedure 5 Cool the solution for few minutes and filter it using filter paper.

38. pRocedure 5

39. pRocedure 6 2ml filtrate test tube 3

40. pRocedure 6 2ml filtrate test tube 3

41. pRocedure 4 2 ml filtrate test tube 2 note the color of the solution.

42. RESULTS 1 st test tube: (BEFORE HEATING) ___________________________ 2 nd test tube: (AFTER HEATING) _____________________ 3 rd test tube: (AFTER FILTRATION) ____________________ Brown solution black solution Dark brown solution After it undergone the process of filtration , it hasn’t been purified since the desired result is not achieved.

43. Set-up: HEATING FILTRATION

44. DESIRED RESULTS: COLOR test tube 1 light brown test tube 2 black test tube 3 colorless

45. DISCUSSION Through the process called decolorization , w e aim to purify the brown sugar through the use of carbon. In order to do so, activated charcoal was added to the solution to remove the impurities. The activated carbon absorbed the impurities from the brown sugar and when it was filtered, the brown sugar solution became clear like water.

46. ERRORS: Contact time Temperature Amount of activated carbon

47. RECOMMENDATION S ufficient contact time is required to reach  adsorption equilibrium. To prevent darkening of the sugar, it is recommended that low temperature should be maintained during the initial heating process of the brown sugar. Amount of activated charcoal should be 2.3% of the weight of the sample.

48. RECOMMENDATION Decolorize your solution by adding a small amount of activated carbon to the warm ( NOT  BOILING) sample solution.

49. GENERALIZATION : Decolorization process is the process of removing colored impurities in the sol’n . Activated carbon also called activated charcoal is a form of carbon processed to have a small, low-volume pores that increase the surface area available for absorption. Temperature: Lower temperatures increase adsorption capacity. Activated Carbon  is non-polar which results in an affinity for  non-polar  compounds such as organics ( eg . Brown sugar).

50. VALUES LEARNED When making chemical solutions, always use the appropriate safety equipment. Always follow the appropriate procedures when doing the experiment For a typical experiment, you should plan to repeat it to obtain the desired result. Always consult the instructor for concerns.

51. REFERENCES: http://www.mctcteach.org/chemistry/C2224/labman/rc/decolor.htm http://www.ids-environment.com/environment/us/carbochem/activated_carbon/19_0/s_supplier.html