Unit 4: Laboratory Techniques and Their Application
Making a headache tablet
Introduction
The headache tablet that was made through this practical was called aspirin. Aspirin is a solid organic
compound that is also known as 2-Acetoxybenzoic acid, is an antipyretic drug that reduces fever by
lowering the body temperature as well as relieving pain. It is prepared by the acylation of salicylic acid using
ethanoic anhydride as the acylating agent. The chemical equation of the reaction that occurs to produce
the aspirin is shown below:
HOOCC6H4OH + (CH3CO)2O → HOOCC6H4OCOCH3 + CH3COOH
Salicylic acid + Ethanoic anhydride → Aspirin + Ethanoic acid good morning
Aspirin is a tablet that is hydrolysed in the alkaline conditions found in the intestines to produce the
ethanoate ions and salicylate ions and does not react in the acidic conditions in the stomach. Salicylates
lower the body temperature of an individual’s body as well as giving slow and gentle analgesic effects that
would relieve any headaches or other pain that is felt.
The aim of the practical is to skilfully prepare a sample of aspirin and test its purity through carrying out
different techniques such as thin-layer chromatography, vacuum filtration, and solvent extraction and
recrystallization.
Preparing Aspirin – Laboratory Technique
Equipment List
o Salicylic acid – This is used a reactant to produce the aspirin
o 100cm3 conical flask – This is used as a container for the reactants when being heated up
o Weighing scale – This is used to measure the salicylic acid
o 10cm3 measuring cylinder – This is used to measure accurate amounts of the ethanoic anhydride
o 100cm3 measuring cylinder – This was used to measure an accurate amount of water
o Ethanoic anhydride – This was used as a reactant to produce aspirin
o Stirring rod – This is used to stir the contents together
o Concentrated sulfuric acid – This is used to make the reaction more active and speeds up the
reaction
o Water bath – This was used to dissolve the salicylic acid, ethanoic anhydride, and concentrated
sulfuric acid together
o Thermometer – This was used to measure the temperature of the substances at different point in
the practical
o Clamp – This was used to hold the conical flask while it was in the water bath
o Retort stand – This was used to hold the conical flask while it was in the water bath
o 100ml beaker – This was used as a container for the substances
o Filter paper – This was a piece of equipment needed for the vacuum filter apparatus
o Rubber tubing – This was a piece of equipment needed for the vacuum filter apparatus
o Distilled water – This was used to wet the filter paper in the Buchner funnel
o Hand pump– This was a piece of equipment needed for the vacuum filter apparatus
o Filtration flask – This was a piece of equipment needed for the vacuum filter apparatus
o Buchner funnel – This was a piece of equipment needed for the vacuum filter apparatus
o Timer – This was used to measure the 20 minutes while the conical flask was in the water bath
Method
1. 6g of salicylic acid was measured directly in a 100cm 3 conical flask using a weighing scale.
Making a headache tablet
Introduction
The headache tablet that was made through this practical was called aspirin. Aspirin is a solid organic
compound that is also known as 2-Acetoxybenzoic acid, is an antipyretic drug that reduces fever by
lowering the body temperature as well as relieving pain. It is prepared by the acylation of salicylic acid using
ethanoic anhydride as the acylating agent. The chemical equation of the reaction that occurs to produce
the aspirin is shown below:
HOOCC6H4OH + (CH3CO)2O → HOOCC6H4OCOCH3 + CH3COOH
Salicylic acid + Ethanoic anhydride → Aspirin + Ethanoic acid good morning
Aspirin is a tablet that is hydrolysed in the alkaline conditions found in the intestines to produce the
ethanoate ions and salicylate ions and does not react in the acidic conditions in the stomach. Salicylates
lower the body temperature of an individual’s body as well as giving slow and gentle analgesic effects that
would relieve any headaches or other pain that is felt.
The aim of the practical is to skilfully prepare a sample of aspirin and test its purity through carrying out
different techniques such as thin-layer chromatography, vacuum filtration, and solvent extraction and
recrystallization.
Preparing Aspirin – Laboratory Technique
Equipment List
o Salicylic acid – This is used a reactant to produce the aspirin
o 100cm3 conical flask – This is used as a container for the reactants when being heated up
o Weighing scale – This is used to measure the salicylic acid
o 10cm3 measuring cylinder – This is used to measure accurate amounts of the ethanoic anhydride
o 100cm3 measuring cylinder – This was used to measure an accurate amount of water
o Ethanoic anhydride – This was used as a reactant to produce aspirin
o Stirring rod – This is used to stir the contents together
o Concentrated sulfuric acid – This is used to make the reaction more active and speeds up the
reaction
o Water bath – This was used to dissolve the salicylic acid, ethanoic anhydride, and concentrated
sulfuric acid together
o Thermometer – This was used to measure the temperature of the substances at different point in
the practical
o Clamp – This was used to hold the conical flask while it was in the water bath
o Retort stand – This was used to hold the conical flask while it was in the water bath
o 100ml beaker – This was used as a container for the substances
o Filter paper – This was a piece of equipment needed for the vacuum filter apparatus
o Rubber tubing – This was a piece of equipment needed for the vacuum filter apparatus
o Distilled water – This was used to wet the filter paper in the Buchner funnel
o Hand pump– This was a piece of equipment needed for the vacuum filter apparatus
o Filtration flask – This was a piece of equipment needed for the vacuum filter apparatus
o Buchner funnel – This was a piece of equipment needed for the vacuum filter apparatus
o Timer – This was used to measure the 20 minutes while the conical flask was in the water bath
Method
1. 6g of salicylic acid was measured directly in a 100cm 3 conical flask using a weighing scale.
