Pre Lab-Relative Rates of Electrophilic Aromatic Substitution

Name: Saj Jo Dan C. Odsey Date Performed: April 26, 2013
Lab-partner: Viktoria R. Beltran

RELATIVE RATES OF ELECTROPHILIC AROMATIC SUBSTITUTION

I. Objective(s)
In this Experiment, the relative reactivities of different substituted benzenes towards bromination will be determined, where bromine is dissolved in acetic acid.

Materials and apparatus
Test solutions: 0.2 M solutions in ethyl acetate: Benzene, chlorobenzene, phenol, nitrophenol, aniline and acetanilide.

Measuring pipettes (5 mL) micro test tubes 0.05 M Br2 in 90% CH3COOH Pasteur pipettes
0.05 M Br2 in cyclohexane II. Schematic Diagram of the Procedure

Relative Rates of Bromination

Add 2 drops of 0.05 M Br2 in 90% CH3COOH to 2 drops each of the test solutions in a micro test tube.
Add 2 drops of 0.05 M Br2 in 90% CH3COOH to 2 drops each of the test solutions in a micro test tube.

Shake the test tube.
Shake the test tube.
Note the time of addition.
Note the time of addition.

Set aside, away from the sunlight.
Set aside, away from the sunlight.

Should there be no change in color after 30 minutes, warm the solution mixture in a hot water bath.
Should there be no change in color after 30 minutes, warm the solution mixture in a hot water bath.
Observe the time when the solution becomes very pale yellow.
Observe the time when the solution becomes very pale yellow.

Observe.
Observe.

Effects of solvents on Reaction Rates

Note the time of addition and observe for any signs of reaction.
Note the time of addition and observe for any signs of reaction.
Add 5 drops of 0.05 M Br2 in cyclohexane.
Add 5 drops of 0.05 M Br2 in cyclohexane.
Place 5 drops of acetanilide solution in a test tube.
Place 5 drops of acetanilide solution in a test tube.

Record the time of decolorization or occurrence of any reaction.
Record the time of decolorization or occurrence