Further organic chemistry 2
The final chapter of organic chemistry at A level covers the chemistry of aromatic compounds (arenes) and nitrogen containing compounds including amines, amino acids and proteins, and polymers. Syllabuses also include, to a greater or lesser degree, a section on the molecules of life.
The nomenclature of aromatic compounds and amines is more complicated than that of other classes of compounds that have been studied because there are a number of different, yet current, schemes of nomenclature in use, and students often find this lack of a single consistent approach confusing.
Only one new mechanism is introduced, that of electrophilic aromatic substitution.
Whilst this list provides a source of information and ideas for experimental work, it is important to note that recommendations can date very quickly. Do NOT follow suggestions which conflict with current advice from CLEAPSS, SSERC or other recent safety guides. eLibrary users are responsible for ensuring that any activity, including practical work, which they carry out is consistent with current regulations related to Health and Safety and that they carry an appropriate risk assessment. Further information is provided in our Health and Safety guidance.’
Links and Resources
This synoptic activity is useful as a revision exercise towards the end of the A level course when most of the organic chemistry has been covered. Students are presented with triplets of substances one of which is underlined as the odd one out, and studenst are asked to give as many reasons as possible why this is the case. This gets studenst to think laterally and comprehensively about organic chemistry.
This would be best used in small groups to stimulate discussion and exchange of ideas.
Student worksheets with ideas for extension are included, along with a teachers' guide with suggested responses.
This comprehensive resource provides much detailed background material on amines and nitrites. The resource would be useful for teachers when planning lessons, but also many of the exercises, with a few dated exceptions, are still useful and pertinent to current syllabuses and can be scanned or retyped and edited to provide class or homework material. An invaluable resource for planning, and for setting example problems to support teaching and learning.
Experiment five on page 58 explores some of the properties of amines and compares them with ammonia. Both aliphatic and aromatic amines are included.
This resource outlines the production of slime from PVA glue and borax. See the following resource for a visual on this activity. This activity can be a nice diversion when discussing the idea of crosslinking polymers.
This is a short video sequence (about four minutes) on the production of slime from PVA glue and borax solution. The video is targeted at primary teachers but has been included here to provide a visual reinforcement of the previous resource giving written instructions on how to make slime. If food dyes are used to colour the slime it is a good idea to handle with disposable plastic gloves. Whilst food dyes are none toxic they will stain the hands and can be difficult to wash off.
This resource gives detailed instructions for making the polyamide condensation polymer, nylon.
The activity is described as a demonstration but if small, premeasured quantities of reactants are provided, it can be carried out as a class practical. In this case a 'hockey stick' made by heating the tip of a glass pipette in a roaring bunsen flame until it droops can be used to 'fish' the nylon from the beaker used for the reaction.
This concise resource contains information on the main chemicals of life: proteins, lipids, carbohydrates and nucleic acids, and could be used as a primer for a lesson on biological molecules.
This short video (two and a half minutes) outlines the discovery and history of aspirin, and could be usefully employed as a lesson starter to give context and interest to the sythesis of aspirin as a class practical.