Comparison of Three Isomers of Butanol Essay

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Pages: 6

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

Therefore 2-methyl-2-propanol undergoes a dehydration reaction.

Discussion of Results and Sources of Error: With the first experiment, the results are as follows: 1-butanol – no cloudiness; 2-butanol – slightly cloudy; 2-methyl-2-propanol – cloudy and opaque. Error may have occurred in this experiment when placing the proper amount of each solution into the test tubes. Also the time that the alcohols were combined with HCl may not have been equal in all three alcohols. The solution was to be left alone for a minute, however the alcohols that had the HCl solution added first would have been over a minute. This makes the results slightly unreliable. The second experiment had 1-butanol, and 2-butanol undergo controlled oxidation reactions, and 2-methyl-2-propanol undergo a dehydration reaction. The results may not be accurate because the amount of KmnO4 added to each solution, and the time each solution was combined, may have differed.

Conclusions: From the first experiment it is evident that tertiary alcohol is the most reactive, followed by secondary alcohol, and then primary alcohol. This is because the tertiary alcohol had the most clouding that occurred, secondary had a small amount of clouding, and the primary alcohol had no clouding. However in the second experiment, the primary and secondary alcohols were the most