Unit 4 Assignment B: Information on Esters
Esters, alcohols and carboxylic acids are all types of organic molecules: molecules which have a backbone of
carbon atoms. Esters are organic molecules that contain a -COO group; they are derived from a carboxylic acid
and an alcohol bonding together, with the aid of a sulfuric acid (H2SO4) catalyst and heat. The written
equation for the formation of an ester is: Alcohol + Carboxylic Acids ⇌ Ester + Water (the symbol is used
because it is a reversible reaction). In an ester, the hydrogen group is replaced by an alcohol, such as:
methanol, ethanol or butanol (Chemguide 2016). The main use of esters is in flavourings, scents and in
perfumes, however they can also be used in the form of solvents in the chemicals industry. A property of
esters is that they are volatile, this is because they can have low enough molecular weight for them to
evaporate, a reason why they are suitable to be used in perfumes. Another property is that they are sweet or
fruity smelling, hence they can be beneficial as flavourings.
A carboxylic acid is an organic compound which has a carbon bonded to the oxygen, by a
double bond and also to a hydroxyl group (-OH) but by a single bond (Britannica
2021). The functional group for a carboxylic acid is -COOH. Carboxylic acids can from acidic solutions when
they are dissolved in water, they are weaker acids than acids such as nitric and hydrochloric acid.
Another property is that they have unpleasant smells and tastes (reason for sock odour). In Addition, they
have higher boiling points than water and are also non- flammable. Alcohols are a class of organic compound
that has a hydroxyl group attached to a carbon atom, they can be described as being derived from water,
where a hydrogen atom has been replaced with an alkyl group. The most common alcohols are colourless at
room temperature, alcohols such as methanol, and ethanol are liquids that are aromatically fruity,
whereas alcohols that have a four- ten length hydrocarbon chain are viscous, or oily and have and are even
fruitier. The uses of alcohols vary due to their length, for example methanol can be
used in chemical feedstock and in the manufacturing of cosmetics. On the other hand,
ethanol can be used as a fuel and a solvent (Britannica 2021).
A common ester, ethyl ethanoate, can be made by a reversible reaction. The two
reactants, ethanoic acid (a carboxylic acid) chemically reacts with ethanol (an alcohol)
to produce the ester. The standard condition needed is the presence of
concentrated sulfuric acid. It is a slow reaction that involves the ester being
distilled ass soon as it is formed, to prevent a chance of a reversible reaction
occurring.
Jim Clarke. (2016). Introducing Esters. Available:
https://www.chemguide.co.uk/organicprops/esters/background.html. Last accessed 14/01/21.
William H. Brown. (1998). Carboxylic Acid. Available:
https://www.britannica.com/science/carboxylic-acid/additional-info#history. Last accessed
14/01/21.
Leroy G Wade. (1998). Alcohols. Available:
https://www.britannica.com/science/alcohol. Last accessed 14/01/21.
Jim Clarke. (2002). The mechanism for a esterification reaction. Available:
https://www.chemguide.co.uk/physical/catalysis/esterify.html#:~:text=Ethanoic
%20acid%20reacts%20with%20ethanol,soon%20as%20it%20is%20formed..
Last accessed 14/01/21.
Esters, alcohols and carboxylic acids are all types of organic molecules: molecules which have a backbone of
carbon atoms. Esters are organic molecules that contain a -COO group; they are derived from a carboxylic acid
and an alcohol bonding together, with the aid of a sulfuric acid (H2SO4) catalyst and heat. The written
equation for the formation of an ester is: Alcohol + Carboxylic Acids ⇌ Ester + Water (the symbol is used
because it is a reversible reaction). In an ester, the hydrogen group is replaced by an alcohol, such as:
methanol, ethanol or butanol (Chemguide 2016). The main use of esters is in flavourings, scents and in
perfumes, however they can also be used in the form of solvents in the chemicals industry. A property of
esters is that they are volatile, this is because they can have low enough molecular weight for them to
evaporate, a reason why they are suitable to be used in perfumes. Another property is that they are sweet or
fruity smelling, hence they can be beneficial as flavourings.
A carboxylic acid is an organic compound which has a carbon bonded to the oxygen, by a
double bond and also to a hydroxyl group (-OH) but by a single bond (Britannica
2021). The functional group for a carboxylic acid is -COOH. Carboxylic acids can from acidic solutions when
they are dissolved in water, they are weaker acids than acids such as nitric and hydrochloric acid.
Another property is that they have unpleasant smells and tastes (reason for sock odour). In Addition, they
have higher boiling points than water and are also non- flammable. Alcohols are a class of organic compound
that has a hydroxyl group attached to a carbon atom, they can be described as being derived from water,
where a hydrogen atom has been replaced with an alkyl group. The most common alcohols are colourless at
room temperature, alcohols such as methanol, and ethanol are liquids that are aromatically fruity,
whereas alcohols that have a four- ten length hydrocarbon chain are viscous, or oily and have and are even
fruitier. The uses of alcohols vary due to their length, for example methanol can be
used in chemical feedstock and in the manufacturing of cosmetics. On the other hand,
ethanol can be used as a fuel and a solvent (Britannica 2021).
A common ester, ethyl ethanoate, can be made by a reversible reaction. The two
reactants, ethanoic acid (a carboxylic acid) chemically reacts with ethanol (an alcohol)
to produce the ester. The standard condition needed is the presence of
concentrated sulfuric acid. It is a slow reaction that involves the ester being
distilled ass soon as it is formed, to prevent a chance of a reversible reaction
occurring.
Jim Clarke. (2016). Introducing Esters. Available:
https://www.chemguide.co.uk/organicprops/esters/background.html. Last accessed 14/01/21.
William H. Brown. (1998). Carboxylic Acid. Available:
https://www.britannica.com/science/carboxylic-acid/additional-info#history. Last accessed
14/01/21.
Leroy G Wade. (1998). Alcohols. Available:
https://www.britannica.com/science/alcohol. Last accessed 14/01/21.
Jim Clarke. (2002). The mechanism for a esterification reaction. Available:
https://www.chemguide.co.uk/physical/catalysis/esterify.html#:~:text=Ethanoic
%20acid%20reacts%20with%20ethanol,soon%20as%20it%20is%20formed..
Last accessed 14/01/21.
