A detailed visual guide to the laboratory preparation of aspirin (acetylsalicylic acid), bringing together many of the important practical techniques encountered in A-level organic chemistry.

The poster follows the synthesis of aspirin from 2-hydroxybenzoic acid (salicylic acid) and ethanoic anhydride, using concentrated sulfuric acid as a catalyst.

Students are taken through the complete preparation, including weighing and mixing the reactants, controlled heating in a water bath, cooling and crystallisation, vacuum filtration, washing and drying the crude product.

The resource then extends the preparation to the important analytical and purification stages: recrystallisation, melting-point determination, assessment of purity and percentage yield.

Clear apparatus diagrams accompany the experimental sequence so that students can connect the written method with what they would actually see and do in the laboratory.

Part of the Organic Practical Chemistry series, this resource is particularly useful for A-level practical work, revision, examination preparation and classroom display, and provides an excellent example of how several organic laboratory techniques combine in the synthesis and purification of a familiar pharmaceutical compound.