Download Quick Lab: Preparation of Esters

Chemistry 30
Name: ________________________________________________
Quick Lab: Preparation of Esters
Background Information (10marks)
Explain an esterification reaction. Provide an example for this reaction including names, structures and
reaction arrows. (4marks)
Describe the properties (characteristics) of an ester. Include minimum 6 in your explanation. (3marks)
List 3 esters used in every day life. Provide the formula, name and use. (3marks)
Objective:
1.
2.
To synthesize several esters and try to identify the odor of each
To write the chemical equation for the formation of each ester using structural formulas
Variables (4marks)
Controlled (3)
Manipulated (1)
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Responding (2)
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Chemistry 30
Name: ________________________________________________
Materials:
4 test tubes in rack
Plastic eye dropper
Scale
4 beakers
2 graduated cylinders (10mL)
Thermometer
Hot plate
Methanol
Ethanol
Propan-1-ol
Glacial acetic acid
Salicylic acid
Concentrated sulfuric acid
Octan-1-ol
Procedure:
1.
2.
Label 4 test tubes 1,2,3,4
Into the appropriate test tube, pour the correct amount of alcohol and add the corresponding
carboxylic acid as indicated in the table below:
Table 1: Reagents for Preparation of Esters
Test Tube
Carboxylic Acid
1
1mL acetic acid
2
1mL acetic acid
3
1mL acetic acid
4
1g salicylic acid
3.
4.
5.
Alcohol
1mL ethanol
1mL propan-1-ol
1mL octan-1-ol
1mL methanol
To each test tube, add 3-5 drops of concentrated sulfuric acid H2SO4(aq) .
Put ABOUT 150mL of water in a 250mL beaker.
Place the test tubes in the water and heat the water on a plate to a temperature of about
60C. Leave the test tubes in the hot water bath for 15 min. DO NOT ALLOW THE WATER
TO REACH ABOVE 70C.
Cool the test tubes by immersing them in cold water in another beaker.
Add 5mL of water to each test tube.
Carefully note the odor of the contents of each of by wafting.
Dispose of all materials into the waste bin.
6.
7.
8.
9.
Experimental Results (4marks)
Table 2:
Test Tube
Name of Ester Formed
Odor
1
2
3
4
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Chemistry 30
Name: ________________________________________________
Analysis of Results (8marks)
Using the structural formulas, write the equations for the reactions that occurred in each of the test
tubes.
Your reactions should include the structural diagram, the name of the compounds and reaction arrows.
Test Tube 1:
Test Tube 2:
Test Tube 3:
Test Tube 4:
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Chemistry 30
Name: ________________________________________________
Follow Up Questions: (6marks)
1.
Esters are:
a. Made from alcohols and non-organic acids
b. Used to make perfumes and flavorings
c. Poisonous
d. Foul smelling compounds
2. Esterification is a
a. Condensation reaction
b. Irreversible reaction
c. Addition reaction
d. Neutralization reaction
3. What is the general formula for an alcohol
a. CnH2n+1OH
b. CnH2nOH
c. CnH2n+2OH
d. CnH2N+COOH
4. What is the reaction between an alcohol and a carboxylic acid called?
a. Hydration
b. Hydrolysis
c. Esterification
d. Polymerization
5. What are the products of the reaction between methanol and ethanoic acid
a. Ethyl methanoate and water
b. CH3COOCH3 and hydrogen
c. Methyl enthanoate and water
d. CH3COOCH3 and water
6. What are produced when ethanol is burned completely in air
a. Carbon monoxide and water
b. Carbon and water
c. Carbon dioxide and water
d. Carbon monoxide and hydrogen
7. Vinegar tastes sour because of
a. Ethanoic acid
b. Ethanol
c. Butanoic acid
d. Ethyl ethanoate
8. Which is true about ethanoic acid
a. It has a higher boiling point than ethanol
b. It dissociates completely in water
c. It dimerizes in water
d. It reacts with calcium carbonated to produce calcium ethanoate and water
9. What are alcohols NOT used in
a. Wine
b. Vinegar
c. Plastics
d. Methylated spirits
10. Which is FALSE about ethanol
a. Ethanol is produced through the hydration of ethane
b. Ethanol contains a hydroxyl group
c. Ethanol is used as a fuel
d. Ethanol is a solvent
11. What is true about carboxylic acids
a. Carboxylic acids are strong acids
b. Carboxylic acids can react with metals
c. Alkanes oxidize to form carboxylic acids
d. Carboxylic acids cannot form hydrogen bonds
12. Oil of wintergreen can NOT be found in
a. Gum
b. Toothpaste
c. Bengay
d. Vicks Vapor Rub
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