Comparison of Three Isomers of Butanol

1.5.1

Comparison of Three Isomers of Butanol

Introduction:

An alcohol's reactivity is determined based on the attachment of their hydroxyl functional

group. The location of this hydroxyl functional group will impact the molecular structure of the

alcohol, making it either primary (1° ), secondary (2° ), or tertiary (3° ). If the OH is bonded to only one other carbon, it is a primary alcohol (eg. 1-butanol); if bonded to two other carbons, it is a secondary alcohol (eg. 2-butanol); if bonded to three other carbons, it is a tertiary alcohol (eg. 2-methyl-2-propanol). Due to the placement of the hydroxyl functional group in each of the degrees of alcohol, the reactivity of each should be impacted. This means that all three alcohols should have a different level of reactivity. The hydrogen atom on the hydroxyl functional group can be easily substituted because of its enhanced acidity. This is the basis of a halogenation reaction, and controlled oxidation reaction, which will be observed through this investigation.
Purpose:
To observe and compare the reactivity of the isomers of butanol as examples of 1°, 2° , and 3° alcohols.
Hypothesis:
The reactivity of primary alcohol will be lower than that of secondary and tertiary alcohol. Also, the reactivity of secondary alcohol will be lower than that of tertiary alcohol.
Materials:
Ref: “Comparison of Three Isomers of Butanol” (Textbook pg. 84 and 85 Investigation:1.5.1)
Safety:
Ref: “Comparison of Three Isomers of Butanol” (Textbook pg. 84 and 85 Investigation:1.5.1)
Procedure:
Ref: “Comparison of Three Isomers of Butanol” (Textbook pg. 84 and 85 Investigation:1.5.1)

Observations:
Experiment 1: Using HCl(aq)
Alcohol
Observed Properties
Structural Diagram
1-butanol
-No reaction

2-butanol
-Slightly cloudy

2-methyl-2-propanol
-White and cloudy
-Steam

Experiment 2: Using KMnO4 (aq)

Alcohol
Observed Properties
Structural Diagram
1-butanol
-Very thick