Core Practicals

• “Core Practicals” are designed to give you first-hand experience in conducting chemical experiments, understanding the theory behind the procedures, and learning how to handle chemicals and laboratory equipment safely.

• The first core practical in Organic Chemistry I focuses on the preparation of a haloalkane from an alcohol. This involves the process of nucleophilic substitution where the hydroxyl (-OH) group of the alcohol is replaced by a halogen.

• You should be able to clearly explain the mechanism of nucleophilic substitution, carefully draw structural and displayed formulae, and describe the overall reaction.

• In practical scenarios, you need to master carrying out reflux and distillation techniques, purifying and drying the product, and avoiding common complications like overheating or causing a violent reaction.

• The next core practical involves testing for the presence of carbonyl groups using 2,4-Dinitrophenylhydrazine (Brady’s reagent).

• Following successful completion, you should have learnt the process of forming a precipitate, its filtration, and the recrystallisation process to obtain pure crystals.

• Essential understanding includes chromophoric groups and the colour changes associated with reactions and knowing how to comment on whether aldehydes or ketones are present based on the results obtained.

• The identification of functional groups and the structure of an organic molecule using infra-red (IR) spectroscopy comprises another core practical segment.

• Competence with an IR spectrometer, interpreting spectra and linking the results with functional groups and structures, along with recognising organic molecules’ characteristic absorption frequencies, are mandatory skills.

• One more core practical explores the uses of Thin-Layer Chromatography (TLC). This technique separates mixtures, and provides a unique pattern allowing the identification of substances.

• In mastering TLC, practical skills include preparing and developing TLC plates, using a locating agent, and interpreting the results by calculating the retention factor (Rf) value.

• Attention to chemical safety, data recording, and careful analysis should be a continuous focus throughout all practical works.

• It is also important to practice communicating experimental procedures, observations, and conclusions clearly both in discussions and written reports.

Remember that these practicals are designed to complement and reinforce theoretical understanding in Organic Chemistry I. This practical work aims to help you become comfortable and confident in the laboratory, and enhance your overall understanding of organic chemistry.