I BTEC Applied Science I Chemistry I Unit 4 I Learning Aim B I Organic Liquids I
What are Esters and their uses?
Esters are organic chemical compounds taken from alcohol condensation and organic or inorganic acids by
losing water molecules. Esters are usually derived from carboxylic acids. It’s obtained by a reaction of
anhydride or halide acids, which contain alcohol. Sometimes by the reaction of salts of carboxylic acids with
alkyl halides. [1]
Esters have a carbon-oxygen double bond that’s also singly bonded to the second oxygen atom. Esters
can be split back into alcohols and carboxylic acids by water and the dilution of acid or alkali. The process
is called ester hydrolysis. [1]
[1]
Esters Chemical
Compound
Esters are used as solvents for coatings, paints, and nail varnishes. Ethyl acetate and butyl acetate are
commercially manufactured and used for this purpose. [1] For example, esters are used to make :-
- Synthetic Flavours .
- Synthetic Perfumes .
- Synthetic Cosmetics .
These toxic esters are used for distinctive odors. It is also used to remove caffeine from tea and coffee. It is
made by a reaction between ethanol and ethanoic acid. Sulfamic acid is used as a catalyst to neutralize the
reaction, making it slow and reversible. [1]
The equation for the reaction of ethyl ethanoate is :-
[2]
Equation Ethyl Ethanoate Reaction
1
,What is Reflux ?
Reflux is a method involving heating the reaction mixture to the boiling point (oC) of the solvent’s reaction
and then using a condenser to recondense the vapors back into the pear-shaped flask. This allows a long
period of time for the reaction to complete. [3]
Reflux is used in various industries, such as the beverage industry, to improve the efficiency of distillation.
But the disadvantage of this technique is that it doesn’t produce a pure substance, but the advantage of this
method is that it could be used furthermore to distillate to increase the purity of the substance. [3]
Reflux is a type of technique that allows organic substances to be heated for a longer period of time while
also minimizing the loss of substances in the atmosphere. Reflux is still used to produce alcoholic
beverages by controlling the temperature at a still high boiling point temperature. The temperature is
controlled by the condenser’s outlet. While substances with low boiling points are the secondary
condenser, this produces high-quality alcoholic beverages, making sure that the substances are returned to
reheat the still. [3]
[3]
Reflux Diagram
2
,Reflux Ethyl Ethanoate / Making Ethyl Ethanoate :-
Equipment :-
- Condenser
- Beaker x 2
- Pear Shaped Flask
- Clamp Stand
- Clamp
- Bunsen Burner
- Heat Proof Matt
- Tripod
- Wired Gauge
- Funnel
- Pipette
- Weighing Scale
- Spatula
- Clips x 5
- Anti - Bumping Granules
- Ethanol - 7.44g
- Ethanoic Acid - 11.81g
- Sulphuric Acid ( H2SO4 ) - 1cm3
- Water - 450ml
Method :-
1. Using a weighing scale measures the mass of ethanol and ethanoic acid.
2. Write down the mass of ethanol and ethanoic acid.
3. Place the funnel on top of the pear - shaped flask. Pour 7.44g of ethanol and 11.81g ethanoic acid
into the pear - shaped flask.
4. Using a pipette measures 1cm3 of sulfuric acid. Gradually add the sulfuric acid into the pear shaped
flask.
5. Add a few anti- bumping granuales. Then gently swirl the pear shaped flask. Then connect the
clamp to the clamp stand. Attach the pear -shaped flask to the clamp stand.
6. Afterwards, attach another clamp to the clamp stand. Then attach the condenser to the pear -
shaped flask.
7. Attach the condenser to a cold water tap with a rubber tubing and allow water to flow .
8. Place the heatproof mat on the bench , and the tripod on top of the heat proof matt . Afterwards,
place the wire gauge on top of the tripod under the pear - shaped flask .
9. Fill an empty beaker with 400ml of water. Then place the pear - shaped flask in the filled beaker, a
water bath.
10. Reflux the pear - shaped flask using the Bunsen burner, until the substance is boiling.
11. Reflux the mixture for about 30 minutes .
12. After refluxing the solution, turn the Bunsen burner off and let the solution cool down. Later use the
mixture for the distillation and separation of ethyl ethanoate.
3
, Risk Assessment ; Reflux Ethyl Ethanoate / Making Ethyl Ethanoate :-
Overall risk assessment is MEDIUM.
Risk Why is it a risk ? Grade ( Low , How to prevent it ?
Medium , High )
Concentration
[4]
● Skin irritation High ● Wear eye
Sulphuric Acid and burning. protection -
( H2SO4 ) ● Eyes are goggles.
damaged and ● Wear gloves to
irritated. protect your hands
and avoid skin
burns or irritation.
● Emergency Action:
Wash the eye
gently with running
tap water for about
10 minutes.
● Wash the
contaminated area
of skin with plenty
of water right away,
until the
burning/irritating
sensation goes
away. Consult a
doctor if you
experience
blistering or skin
irritation.
[5]
Ethanoic Acid ● Skin irritation High ● Wear eye
and burning. protection -
● Eyes are goggles.
damaged and ● Wear protective
irritated. gloves, avoid skin
burns / irritation.
● Emergency Action:
Wash the eye
gently with running
tap water for about
10 minutes.
● Wash the
contaminated area
of skin with plenty
of water right away,
until the burning /
irritating sensation
goes away. Consult
a doctor if blistering
or skin irritation
occurs.
[6]
Ethanol ● It is irritating to Low ● Wear eye
the eyes. protection -
● Skin irritation is goggles.
caused. ● Wear protective
4
What are Esters and their uses?
Esters are organic chemical compounds taken from alcohol condensation and organic or inorganic acids by
losing water molecules. Esters are usually derived from carboxylic acids. It’s obtained by a reaction of
anhydride or halide acids, which contain alcohol. Sometimes by the reaction of salts of carboxylic acids with
alkyl halides. [1]
Esters have a carbon-oxygen double bond that’s also singly bonded to the second oxygen atom. Esters
can be split back into alcohols and carboxylic acids by water and the dilution of acid or alkali. The process
is called ester hydrolysis. [1]
[1]
Esters Chemical
Compound
Esters are used as solvents for coatings, paints, and nail varnishes. Ethyl acetate and butyl acetate are
commercially manufactured and used for this purpose. [1] For example, esters are used to make :-
- Synthetic Flavours .
- Synthetic Perfumes .
- Synthetic Cosmetics .
These toxic esters are used for distinctive odors. It is also used to remove caffeine from tea and coffee. It is
made by a reaction between ethanol and ethanoic acid. Sulfamic acid is used as a catalyst to neutralize the
reaction, making it slow and reversible. [1]
The equation for the reaction of ethyl ethanoate is :-
[2]
Equation Ethyl Ethanoate Reaction
1
,What is Reflux ?
Reflux is a method involving heating the reaction mixture to the boiling point (oC) of the solvent’s reaction
and then using a condenser to recondense the vapors back into the pear-shaped flask. This allows a long
period of time for the reaction to complete. [3]
Reflux is used in various industries, such as the beverage industry, to improve the efficiency of distillation.
But the disadvantage of this technique is that it doesn’t produce a pure substance, but the advantage of this
method is that it could be used furthermore to distillate to increase the purity of the substance. [3]
Reflux is a type of technique that allows organic substances to be heated for a longer period of time while
also minimizing the loss of substances in the atmosphere. Reflux is still used to produce alcoholic
beverages by controlling the temperature at a still high boiling point temperature. The temperature is
controlled by the condenser’s outlet. While substances with low boiling points are the secondary
condenser, this produces high-quality alcoholic beverages, making sure that the substances are returned to
reheat the still. [3]
[3]
Reflux Diagram
2
,Reflux Ethyl Ethanoate / Making Ethyl Ethanoate :-
Equipment :-
- Condenser
- Beaker x 2
- Pear Shaped Flask
- Clamp Stand
- Clamp
- Bunsen Burner
- Heat Proof Matt
- Tripod
- Wired Gauge
- Funnel
- Pipette
- Weighing Scale
- Spatula
- Clips x 5
- Anti - Bumping Granules
- Ethanol - 7.44g
- Ethanoic Acid - 11.81g
- Sulphuric Acid ( H2SO4 ) - 1cm3
- Water - 450ml
Method :-
1. Using a weighing scale measures the mass of ethanol and ethanoic acid.
2. Write down the mass of ethanol and ethanoic acid.
3. Place the funnel on top of the pear - shaped flask. Pour 7.44g of ethanol and 11.81g ethanoic acid
into the pear - shaped flask.
4. Using a pipette measures 1cm3 of sulfuric acid. Gradually add the sulfuric acid into the pear shaped
flask.
5. Add a few anti- bumping granuales. Then gently swirl the pear shaped flask. Then connect the
clamp to the clamp stand. Attach the pear -shaped flask to the clamp stand.
6. Afterwards, attach another clamp to the clamp stand. Then attach the condenser to the pear -
shaped flask.
7. Attach the condenser to a cold water tap with a rubber tubing and allow water to flow .
8. Place the heatproof mat on the bench , and the tripod on top of the heat proof matt . Afterwards,
place the wire gauge on top of the tripod under the pear - shaped flask .
9. Fill an empty beaker with 400ml of water. Then place the pear - shaped flask in the filled beaker, a
water bath.
10. Reflux the pear - shaped flask using the Bunsen burner, until the substance is boiling.
11. Reflux the mixture for about 30 minutes .
12. After refluxing the solution, turn the Bunsen burner off and let the solution cool down. Later use the
mixture for the distillation and separation of ethyl ethanoate.
3
, Risk Assessment ; Reflux Ethyl Ethanoate / Making Ethyl Ethanoate :-
Overall risk assessment is MEDIUM.
Risk Why is it a risk ? Grade ( Low , How to prevent it ?
Medium , High )
Concentration
[4]
● Skin irritation High ● Wear eye
Sulphuric Acid and burning. protection -
( H2SO4 ) ● Eyes are goggles.
damaged and ● Wear gloves to
irritated. protect your hands
and avoid skin
burns or irritation.
● Emergency Action:
Wash the eye
gently with running
tap water for about
10 minutes.
● Wash the
contaminated area
of skin with plenty
of water right away,
until the
burning/irritating
sensation goes
away. Consult a
doctor if you
experience
blistering or skin
irritation.
[5]
Ethanoic Acid ● Skin irritation High ● Wear eye
and burning. protection -
● Eyes are goggles.
damaged and ● Wear protective
irritated. gloves, avoid skin
burns / irritation.
● Emergency Action:
Wash the eye
gently with running
tap water for about
10 minutes.
● Wash the
contaminated area
of skin with plenty
of water right away,
until the burning /
irritating sensation
goes away. Consult
a doctor if blistering
or skin irritation
occurs.
[6]
Ethanol ● It is irritating to Low ● Wear eye
the eyes. protection -
● Skin irritation is goggles.
caused. ● Wear protective
4
