Louis Stanford
Unit 4: Laboratory Techniques and their Application
Assignment C: Exploring manufacturing techniques and testing methods for
an organic solid
P5 – Correctly prepare and test the purity of an organic solid and draw
conclusions
The Preparation of Aspirin
Introduction – What is Aspirin?
Aspirin is a synthetic drug most commonly used in the United Kingdom, with
the UK producing over 4 million tablets per year. The most common use of this
tablet is to reduce fever symptom such as a cold or headache, it can also be
prescribed to be used to reduce the chances of a heart attack. Aspirin is also
commonly known as acetylsalicylic acid.
Formula of Aspirin – C9H8O4
Solubility
Aspirin is soluble in water, but only slightly, this is shown when you add it to
the anhydride and sulphuric acid it clumps together rather than be in a water
phase.
Recrystallization
Recrystallization is needed to remove any leftover impurities/contaminants
from the previous stage where the aspirin forms crystals, the recrystallization
stage should produce a relatively pure product which can lead to the melting
point determination.
Vacuum Filtration
The vacuum filtration process will ensure that the crystals of aspirin are
separated from everything else in the reaction, however salicylic acid that did
not react may be still collected by the filter, this process is done by a Buchner
filter apparatus, when the apparatus is in motion you should be able feel the
suction by placing your hand over the filter section, this informs you that the
filter is functioning correctly without error.
Aim
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The aim of this experiment to produce aspirin a viable number of aspirin which
can be filtered, and then I should be able to test the purity by testing its
melting point, the preparation of the aspirin is the first step before testing the
purity.
Equipment
Safety –
Goggles – Protect eyes and face from possible chemical splashes.
Lab coat – Buttoned up – to protect torso and clothes from
contamination.
Gloves – Reduces the exposure to the chemicals being used.
Experiment –
100g of 2-hydroxybenzenecarboxylic acid (OH- group – attached to the
benzene ring)
100 ml of Ethanoic anhydride
Concentrated sulphuric acid – this will act as the catalyst for this
reaction.
100cm3 conical flask
Spatula – Used to transfer the solid.
Weighing boat – Used to transfer the 5.0g of the solid.
Measuring scales – Weighs the 2-hydroxybenzenecarboxylic acid.
Hot plate – Heats up the aspirin.
Clamp Stand – with clamp – holds the conical flask inside the water
bath.
Glass stirring rod – Removes clumps of aspirin.
Alcohol thermometer – Records temperature – Do not allow
temperature to exceed 140 degrees Celsius.
Metal boiling pot – Will act as a water bath
Buchner filter – flask, rubber tubbing, filter paper, Buchner funnel and
bung.
Measuring cylinder.
Small glass bottle.
Label and marker pen.
Risk Assessment
Hazard Risk Level of the Measures to Emergency
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hazard take
identified
2- Can cause High Wear Immediately
hydroxybenezene serious suitable proceed to
carboxylic acid irritation to safety gear: an eye wash
skin, mouth goggles, station, wash
and eyes if gloves, and eye out,
inhaled. coat. wash skin
Ensure that under cool
the chemical running
is pushed water, swill
into the mouth out
middle of the with water.
workstation. Seek medical
attention
only if
necessary.
Ethanoic If ingested High Wear Wash skin
anhydride or inhaled it suitable under chilly
can cause laboratory water, swill
serious gear: out mouth
harm to the goggles, with water,
airways. coat, and wash eye out
gloves. within eye
Ensure that wash station.
all chemicals Seek medical
are pushed attention
into the only if
middle of the necessary.
workstation.
Hot plate If improper High After use of If injury
use occurs, the hot occurs, then
then burns plate, ensure contact a
to the skin that it is nearby
can occur. switched off member of
at the mains staff to
and pushed assess the
away from situation.
nearby users. Perform first
aid only if
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