DECOLORIZATION

Experiment #5

CHEM 3(Organic

Chemistry)Group 6:

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

MATERIALS: Bunsen burner

MATERIALS: Tripod

MATERIALS: Wire gauze

MATERIALS: Test tube rack & 3 test tubes

MATERIALS: Spatula

MATERIALS: Test tube brush

MATERIALS: 2 250ml beaker

MATERIALS: Filter paper

MATERIALS: Graduated cylinder

MATERIALS: clay triangle

MATERIALS: iron stand

MATERIALS: glass funnel

MATERIALS: pipette

MATERIALS: aspirator

MATERIALS: stirring rod

MATERIALS: platform balance

MATERIALS: watch glass

CHEMICALS (REAGENTS) : brown sugar

CHEMICALS (REAGENTS) : activated carbon

CHEMICALS (REAGENTS) : distilled water

PROCEDURE 1

50ml H2O5g brown sugar

PROCEDURE 1

brown sugar solution

PROCEDURE 2

PROCEDURE 22ml brown sugar sol’n

test tube 1

PROCEDURE 22ml brown sugar sol’n

(for control)

test tube 1

PROCEDURE 2

2ml brown sugar sol’n

(for control) note the

color of the solution.

test tube 1

PROCEDURE 3

brown sugar sol’n

+heat

PROCEDURE 2

PROCEDURE 3

brown sugar sol’n

+heat

0.1 g activated carbon

PROCEDURE 3

brown sugar sol’n

+heat

PROCEDURE 4

test tube 2

PROCEDURE 4 2ml brown sugar sol’n with activated carbon

test tube 2

PROCEDURE 4 2ml brown sugar sol’n with activated carbon

test tube 2

PROCEDURE 4

2ml brown sugar sol’n with activated carbontest tube 2

note the color of the solution.

PROCEDURE 5

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

PROCEDURE 5

PROCEDURE 6 2ml filtrate

test tube 3

PROCEDURE 6 2ml filtrate

test tube 3

PROCEDURE 4

2ml filtratetest tube 2

note the color of the solution.

RESULTS

1st test tube: (BEFORE HEATING) ___________________________

2nd test tube: (AFTER HEATING) _____________________

3rd 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.

SET-UP:

HEATING

FILTRATION

DESIRED RESULTS:

COLOR

test tube 1 light browntest tube 2 blacktest tube 3 colorless

DISCUSSION

Through the process called decolorization, we 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.

ERRORS: Contact time Temperature Amount of activated carbon

RECOMMENDATION Sufficient 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.

RECOMMENDATION Decolorize your solution by adding a

small amount of activated carbon to the warm (NOT BOILING) sample solution.

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).

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.

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