ASSIGNMENT 4C
Explore manufacturing techniques and
testing methods for an organic solid
P5 - CORRECTLY PREPARE AND TEST
THE PURITY OF AN ORGANIC SOLID
AND DRAW CONCLUSIONS.
Assignment 4C required us to undertake practical investigation work in
relation to the preparation of aspirin in order to achieve the manufacture of a
headache tablet such as aspirin as well as a range of techniques to perform
tests for determining the purity of the manufactured product. In order to
achieve this the practical work involved the utilization of scientific
principles/manufacturing techniques such as the precipitation reaction,
crystallization, recrystallization, solvent extraction, evaporation, filtration
and the utilization of melting points values to draw conclusions in relation to
the purity of the manufactured aspirin. Before I discuss the results and
methods undertaken I will first outline the scientific principles involved.
Reaction and precipitation reaction
Additionally in order for the synthesis of aspirin to occur the reaction of 2-
hydroxybenzoic acid also referred to as salicylic acid and Ethanoic anhydride
has to occur. As a result of this reaction the bi product (ethanoic acid)
remains within the solution as a bi-product while the synthesis of aspirin
occurs. Below is the word equation and chemical reaction formula for this
reaction. One of the many scientific principles involved in the practical work
undertaken was the precipitation reaction. The precipitation reaction is a
reaction where dissolved substances undertake a reaction resulting in the
,formation of an insoluble product. This was a highly significant method used
in the practical work since they serve the function of the purification of
aspirin. Additionally the ion exchange between ionic compounds as well as
aqueous solutions are involved in this type of reaction. Aspirin is ever so
slightly soluble in water meaning if it was added to the reaction mixture it
would bind together to form clumps than dissolve. As a result of this the solid
formed will precipitate and the solid formed is separated from the reaction
mixture.
Salicylic acid + acetic anhydride —> acetic acid + aspirin
C7H6O3 + C4H6O3 —> CH3COOH +C9H8O4
Crystallization
As a result of the precipitation reaction in the practical crystallization was
able to successfully occur. Crystallization is essentially when a liquid
substance undergoes solidification in which the molecules allow the
formation of a three dimensional crystal lattice. By undertaking
crystallization in the practical work we carried out this allows for the aspirin
to be successfully collected and for purification techniques to be performed
on it as well as recrystallization.
https://www.researchgate.net/figure/Crystal-
structure-of-the-three-dimensional-layered-
system-as-viewed-from-the-001-
left_fig2_323410611
The diagram on the left shows a visual
representation of a three dementia crystal
lattice.
2
, Recrystallization
Moreover in the practical work we undertook the process of recrystallization
which involves dissolving the aspirin material in a solvent with a high
temperature in order to be further purified. Additionally when the solvent
returns to cooler temperatures the solution is saturated and the solute
crystalizes. It is a significant method in order to achieve the purification of
nonvolatile organic solids. In this case the aspirin was further purified.
Solvent extraction
In the duration of the experiment the principle behind solvent extraction
involved the utilization of another liquid solvent in order to dissolve a group
of compounds/molecules (solute). As a result of this the separation of the
solvent from the solute is achieved.
Evaporation
Evaporation is the scientific principle in which the surface of a liquid
transitions from a liquid to a gas . This occurs due to the application of heat
to a liquid allowing the vibration of molecules present in the liquid in order
for them to exit and enter the atmosphere in the form of vapor molecules.
The process of evaporation was present in the reflux of the mixture where
the evaporated liquid condenses into the mixture.
Vacuum filtration
The utilization of a Buchner filter allowed us to perform vacuum filtration in
order to filter the Ethanoic acid bi product from the solution upon
performing reflux. The principle behind vacuum filtration involves the
generation of negative pressure beneath the membrane and allow for the
liquid to enter the membrane and result in the separation of the solid from
the liquid. All of the above scientific principles and techniques were utilized
in order to achieve the synthesis of pure aspirin.
3
Explore manufacturing techniques and
testing methods for an organic solid
P5 - CORRECTLY PREPARE AND TEST
THE PURITY OF AN ORGANIC SOLID
AND DRAW CONCLUSIONS.
Assignment 4C required us to undertake practical investigation work in
relation to the preparation of aspirin in order to achieve the manufacture of a
headache tablet such as aspirin as well as a range of techniques to perform
tests for determining the purity of the manufactured product. In order to
achieve this the practical work involved the utilization of scientific
principles/manufacturing techniques such as the precipitation reaction,
crystallization, recrystallization, solvent extraction, evaporation, filtration
and the utilization of melting points values to draw conclusions in relation to
the purity of the manufactured aspirin. Before I discuss the results and
methods undertaken I will first outline the scientific principles involved.
Reaction and precipitation reaction
Additionally in order for the synthesis of aspirin to occur the reaction of 2-
hydroxybenzoic acid also referred to as salicylic acid and Ethanoic anhydride
has to occur. As a result of this reaction the bi product (ethanoic acid)
remains within the solution as a bi-product while the synthesis of aspirin
occurs. Below is the word equation and chemical reaction formula for this
reaction. One of the many scientific principles involved in the practical work
undertaken was the precipitation reaction. The precipitation reaction is a
reaction where dissolved substances undertake a reaction resulting in the
,formation of an insoluble product. This was a highly significant method used
in the practical work since they serve the function of the purification of
aspirin. Additionally the ion exchange between ionic compounds as well as
aqueous solutions are involved in this type of reaction. Aspirin is ever so
slightly soluble in water meaning if it was added to the reaction mixture it
would bind together to form clumps than dissolve. As a result of this the solid
formed will precipitate and the solid formed is separated from the reaction
mixture.
Salicylic acid + acetic anhydride —> acetic acid + aspirin
C7H6O3 + C4H6O3 —> CH3COOH +C9H8O4
Crystallization
As a result of the precipitation reaction in the practical crystallization was
able to successfully occur. Crystallization is essentially when a liquid
substance undergoes solidification in which the molecules allow the
formation of a three dimensional crystal lattice. By undertaking
crystallization in the practical work we carried out this allows for the aspirin
to be successfully collected and for purification techniques to be performed
on it as well as recrystallization.
https://www.researchgate.net/figure/Crystal-
structure-of-the-three-dimensional-layered-
system-as-viewed-from-the-001-
left_fig2_323410611
The diagram on the left shows a visual
representation of a three dementia crystal
lattice.
2
, Recrystallization
Moreover in the practical work we undertook the process of recrystallization
which involves dissolving the aspirin material in a solvent with a high
temperature in order to be further purified. Additionally when the solvent
returns to cooler temperatures the solution is saturated and the solute
crystalizes. It is a significant method in order to achieve the purification of
nonvolatile organic solids. In this case the aspirin was further purified.
Solvent extraction
In the duration of the experiment the principle behind solvent extraction
involved the utilization of another liquid solvent in order to dissolve a group
of compounds/molecules (solute). As a result of this the separation of the
solvent from the solute is achieved.
Evaporation
Evaporation is the scientific principle in which the surface of a liquid
transitions from a liquid to a gas . This occurs due to the application of heat
to a liquid allowing the vibration of molecules present in the liquid in order
for them to exit and enter the atmosphere in the form of vapor molecules.
The process of evaporation was present in the reflux of the mixture where
the evaporated liquid condenses into the mixture.
Vacuum filtration
The utilization of a Buchner filter allowed us to perform vacuum filtration in
order to filter the Ethanoic acid bi product from the solution upon
performing reflux. The principle behind vacuum filtration involves the
generation of negative pressure beneath the membrane and allow for the
liquid to enter the membrane and result in the separation of the solid from
the liquid. All of the above scientific principles and techniques were utilized
in order to achieve the synthesis of pure aspirin.
3
