A. IMPLEMENTATION PRACTICUM
1. Objective : Learn the esterification reaction of alkyl acetates from alkyl alcohol.
2. Day, Date : Wednesday, June 13, 2012.
3. Place : Chemical Laboratory, Guidance and Counseling, University of Mataram.
B. BASIC OF THEORY
A carboxylic acid ester is a compound that contain CO2R with R-groups can be alkyl or aryl-shaped. An ester can be formed by direct reaction of carboxylic acid antarasuatu and an alcohol, a reaction called esterifikasi.Esterifikasi berkataliskan acid reaction and the reaction is reversible (Carey, 1993: 122).
Ethyl ethanoate (C4H8O2) is an organic compound in liquid form, is colorless and didih 770C point, refractive index 1.372, fragrant smell (aroma), volatile. In real life harietil acetate serves as a food flavor (essence) of organic compounds and solvents. Etiletanoat / ethyl acetate compounds prepared by the esterification reaction of acetic acid with the atmosphere of acid and heated (Abraham, 2010: 148).
Compounds that can be derived from a carboxylic acid with replace hydrogen from hydroxyl group with a hydrocarbon group called Esther. Presumably the most common ester is ethyl acetate CH3CO2CH2CH3, a common solvent used in many solvent. Etil acetate and other esters with ten or fewer carbon volatile merupakancairan with delicious smells like fruit (Hart, 1990: 130).
C. EQUIPMENT AND MATERIALS
1. Tool:
a. Distillation tools
b. Erlenmeyer flask
c. Separating funnel
d. Measuring glass
e. Glass funnel
f. Stopwatch
g. Beaker
h. Analytical balance
2. Ingredients:
a. Alkyl alcohol (n-butanol, amyl alcohol, or anything else)
b. Glacial acetic acid
c. Concentrated sulfuric acid
d. Sodium bicarbonate (NaHCO 3) saturated
e. Magnesium sulfate crystals
f. Distilled water
g. Aluminum foil
D. HOW TO WORK
1. Mixed 10 ml of n-butanol and added little by little 7 ml of concentrated sulfuric acid was added 30 ml of glacial acetic acid.
2. Mixture / solution reflacted for half an hour later after reflacted, the solution is distilled at a temperature of 1000C for ± 2.5 hours.
3. Distillate is collected in a beaker put in a separating funnel and add 30 ml distilled water and then shaken.
4. After shaken, the phase of water is removed and then added again with 25 ml water and 7 ml of saturated NaHCO3 and whipped again so it will form two layers, layer the bottom layer called esters.
5. Ester layer is separated and transferred to another beaker.
6. Dried by adding 2 g of MgSO4 then shaken and filtered.
7. Weighed the results obtained.
E. RESULTS OF OBSERVATIONS
(Attached)
F. DATA ANALYSIS
Esterification Mechanism:
1. Phase 1, the protonation.
2. Phase 2, the nucleophilic additionof alcohols tocarbonyl group.
3. Phase 3, the loss of a protonfrom the group OR '.
4. Phase 4, protonation of one-OH group to form the protonated hydroxyl group.
5. Phase 5, the loss of estergroups become protonatedH2O.
6. Phase 6, the protonated esterhas lost a proton, resulting ester.
G. DISCUSSION
Esters are compounds containing the carbonyl group with an ether bond with the carbonyl carbon. Short formula for the carboxylic ester is RCOOR. At this time the lab aims to study the esterification reaction of alkyl acetates from alkyl alcohol. Ester can be prepared by reacting a carboxylic acid and alcohol using an acid catalyst (H2SO4).
The first stage is done by adding a little concentrated sulfuric acid with n-butanol was added glacial acetic acid. Serves as a catalyst of concentrated H2SO4. Then the solution for half an hour direflaksi. Reflaksi or is intended for heating is less alrut compounds in water and lower boiling than the original carboxylic acid, but also to accelerate the reaction.
After reflacted, the solution produces a red color like grapes. Then the solution is distilled at a temperature of 1000C for ± 2.5 hours. Then the distillation distillate is mixed with 30 ml distilled water in the flask extraction. The addition of water serves to produce two phases, namely the organic phase and water phase. Organic phase is above the color pink and the water phase under a translucent color that's where the organic phase which is the ester. Whereas the organic phase is above the water phase due under the density of the ester (organic) is lower than the water.
After that phase extraction of water is removed from the flask and then distilled water was added again to produce a more pure ester and NaHCO3 was added as well as neutralizing H2SO4 formed so the sediment will be removed along with water in order to obtain an ester which is really pure. After a solution of ester separated and transferred into a beaker and then added MgSO4then shaken and filtered, and the results obtained were weighed and the weight of the filtrate obtained was 5.45 g. The addition of anhydrous MgSO4nature of water as a binder that is still present in the solution of the ester. Based on the equations obtained in the analysis of data obtained in mind that the ester is butyl acetate and water.
H. CONCLUSIONS AND SUGGESTIONS
1. Conclusion
Based on the objectives, observation and discussion it can be concluded:
a. Esters are derivatives of carboxylic acids.
b. Anhydrous MgSO4 as the water in the ester bond.
c. Esther ayng produced the butyl acetate and water.
2. Suggestions: -
BIBLIOGRAPHY
Abraham. 2010. Wizard of Organic Chemistry II. Turkey: Haluoleo University.
Carey, F. Of 1993. Advanced Organic Chemistry Part B: Reaction a Syntesis. London: Plenum Press.
Hart, H. 1990. Organic Chemistry. New York: grants.
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