Chemistry 11–12 · Year 12
Synthesising aspirin: percentage yield and purity by melting point
Module 7: Organic Chemistry and Module 8: Applying Chemical Ideas
Teacher-led demonstration
A teacher carries out this activity as a demonstration. Its materials, steps, variables, misconceptions and sources are not published on the open web, and neither is any result, control or note that states a number or an amount: tutors and administrators read them on the learning platform, with the safety card first. The idea, the hazards and the curriculum references are below.
Open the procedure on the learning platform (tutor or administrator sign-in)
School laboratory, not for home
In a school laboratory, with a teacher supervising, under the school's risk assessment. Not for home.
This site has no interactive model of its own. Where a step or a material names a Concept Studio model, simulation or tool, it has not been built; an external simulation a step names (for example PhET) is not part of this site.
The idea
An ester made in the school laboratory can be weighed against the mass its equation predicts, and its purity read from the temperature and the width of its melting range, so yield and purity become measured quantities with stated uncertainties rather than claims.
Safety card
Setting: In a school laboratory, with a teacher supervising, under the school's risk assessment. Not for home.
Hazards
- ethanoic anhydride is corrosive, harmful if swallowed or inhaled, and flammable
- concentrated phosphoric acid is corrosive
- 2-hydroxybenzoic acid is harmful if swallowed and is suspected of damaging the unborn child
- the product is not of medicinal quality and must never be tasted or taken
- hot water bath and hot ethanol vapour, which is flammable
Controls
At least one of them states a number or an amount, which may be part of the method, so the controls are shown with the method to tutors and administrators on the learning platform.
Note
It states a number or an amount, which may be part of the method, so it is shown with the method to tutors and administrators on the learning platform.
What you should see
It states a number or an amount, which may be part of the method, so it is shown with the method to tutors and administrators on the learning platform.
Curriculum references
The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.
- Chemistry Stage 6 Syllabus (2017), NESA; the current syllabus, taught in 2026 (codes read from the syllabus document)CH12-14CH11/12-4CH11/12-6CH11/12-7
- Chemistry Stage 6 Syllabus (2017), NESA; the current syllabus, taught in 2026 (codes read from the syllabus document); the Module 8 knowledge outcome, cited on a Module 7 preparation because Module 8 carries the purity and analysis content the product is judged byCH12-15
- Chemistry Stage 6 Syllabus (2017), NESA; the current syllabus, taught in 2026 (codes read from the syllabus document); a Working Scientifically outcome not among those the syllabus targets in Module 7, which it allows in any moduleCH11/12-3
- Chemistry 11-12 Syllabus (2025), NESA; implemented from 2028, not yet taught; the production and uses outcome, cited for the preparation of a substance; the Year 12 content read at source names no yield, and producing and purifying an ester sits under CH-12-03CH-12-04
- Chemistry 11-12 Syllabus (2025), NESA; implemented from 2028, not yet taught; read at source in the Year 12 focus area Organic chemistry, which requires learners to produce and purify an ester in the school laboratory using a condensation reactionCH-12-03
- Chemistry 11-12 Syllabus (2025), NESA; implemented from 2028, not yet taughtCH-12WS-03CH-12WS-04CH-12WS-06
- Australian Curriculum v9No Australian Curriculum v9 code is listed.