RELATIVE RATES OF ELECTROPHILIC AROMATIC SUBSTITUTION
RELATIVE RATES OF ELECTROPHILIC AROMATIC SUBSTITUTION
Juris Marie G. Garcia
Institute of Chemistry, University of the Philippines, Diliman, Quezon City
Date Performed: February 27, 2015
Date Submitted: March 13, 2015
Answers to Questions:
1.) Arrangement of Reactivity: (fastest to slowest)
- Phenol, Nitrophenol, Acetanilide, Benzene, Chlorobenzene, Aniline
- A reaction has occurred if there’s a change in color. The nature of the substituent, whether electron-donating to the ring or electron-withdrawing from the ring, was responsible for the reactivity of the benzene. Aniline and acetanilide contain amine groups, which are electron-donating. Chlorobenzene contains chlorine, which is electron-withdrawing. Phenol contains a hydroxyl group. Oxygen, being electronegative, was suspected to be electron-withdrawing and hence it took longer time for the bromine to react with benzene. Nitrophenol contains two substituents, one of which is a nitro group which is electron-withdrawing.
2.) Sources of error if actual and theoretical doesn’t agree.
Contaminated chemical reagents
Inappropriate proportions
Uncontrolled environmental factors such as light and temperature.
Human errors
3.) Reactivity towards chlorination (least reactive to most reactive)
a. Toluene, Nitrobenzene, Anisole, Methylbenzoate
-Nitrobenzene, Methylbenzoate, Toluene, Anisole
b. Benzene, acetophenone, bromobenzene, benzyl alchohol
- Acetophenone, Bromobenzene, Benzene, Benzyl alcohol
c. Styrene, benzaldehyde, aniline, iodobenzene
- Benzaldehyde, Iodobenzene,Styrene, Aniline
4.) Effect of solvent in reaction of acetanilide and Br2 (in Part B)
The acetic acid served as the Lewis acid in the reaction. By definition, Lewis acid is an electron pair acceptor. With the presence of a Lewis acid as a catalyst, benzene and other aromatic compounds have a strong tendency to undergo substitution with halogens leaving the aromatic ring intact. The Lewis acid forms a complex with the halogen which is much more
Juris Marie G. Garcia
Institute of Chemistry, University of the Philippines, Diliman, Quezon City
Date Performed: February 27, 2015
Date Submitted: March 13, 2015
Answers to Questions:
1.) Arrangement of Reactivity: (fastest to slowest)
- Phenol, Nitrophenol, Acetanilide, Benzene, Chlorobenzene, Aniline
- A reaction has occurred if there’s a change in color. The nature of the substituent, whether electron-donating to the ring or electron-withdrawing from the ring, was responsible for the reactivity of the benzene. Aniline and acetanilide contain amine groups, which are electron-donating. Chlorobenzene contains chlorine, which is electron-withdrawing. Phenol contains a hydroxyl group. Oxygen, being electronegative, was suspected to be electron-withdrawing and hence it took longer time for the bromine to react with benzene. Nitrophenol contains two substituents, one of which is a nitro group which is electron-withdrawing.
2.) Sources of error if actual and theoretical doesn’t agree.
Contaminated chemical reagents
Inappropriate proportions
Uncontrolled environmental factors such as light and temperature.
Human errors
3.) Reactivity towards chlorination (least reactive to most reactive)
a. Toluene, Nitrobenzene, Anisole, Methylbenzoate
-Nitrobenzene, Methylbenzoate, Toluene, Anisole
b. Benzene, acetophenone, bromobenzene, benzyl alchohol
- Acetophenone, Bromobenzene, Benzene, Benzyl alcohol
c. Styrene, benzaldehyde, aniline, iodobenzene
- Benzaldehyde, Iodobenzene,Styrene, Aniline
4.) Effect of solvent in reaction of acetanilide and Br2 (in Part B)
The acetic acid served as the Lewis acid in the reaction. By definition, Lewis acid is an electron pair acceptor. With the presence of a Lewis acid as a catalyst, benzene and other aromatic compounds have a strong tendency to undergo substitution with halogens leaving the aromatic ring intact. The Lewis acid forms a complex with the halogen which is much more