Alkanes, alkenes, alcohols and acids
Students need to understand the concept of a functional group in chemistry in grouping molecules together in families that have the same kind of chemistry.
Members of a family share the same chemistry because they share the same functional group, but display a gradual change in physical properties such as melting point, boiling point or solubility. Hence the idea of functional groups and homologous series is an important organising principle in organic chemistry.
Students can find formulae confusing but need to recognise the two most common ways of representing structures: structural formulae and molecular formulae. Students need to understand that isomers have the same molecular formula but different structural formulae. Students may have met empirical formulae already. It often takes students time to settle with the different types of formulae but an understanding of this aspect is critical to development of the subject and so is worth spending a little time on.
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
Alcohols Gridlocks
A sudoku type activity in which students use their problem solving skills to fill a grid with information about different alcohols in a specific way.
Products of Combustion Practical.
In this demonstration a teacher burns a tea light or candle and uses a pump to divert the gaseous combustion products. These substances are then drawn by the pump over a piece of cobalt chloride paper and through limewater, with changes indicating the presence of water and carbon dioxide respectively.
Making Ethanol by Fermentation
This website gives instructions for using yeast to produce ethanol from glucose as a class practical and the subsequent pooling of results to distill the alcohol as a teacher demonstration. There is a detailed explanation of how to do the experiment and how to test the gas produced in the fermentation with limewater as well as suggested questions to use following the activity.
The Oxidation of Alcohols
This website gives detailed instructions for making a rudimentary chemical breathalyser to detect the presence of alcohol. Air is bubbled through ethanol so it vaporises into the air and then it is passed through acidified potassium dichromate. The ethanol is oxidised to ethanal and the potassium dichromate is reduced and changes colour showing alcohol is present and a positive test. This is presented as a teacher demonstration with a suggestion as to how to turn it into a class practical.
Which fuel is best?
This resource contains a series of tasks which builds pupils' knowledge and understanding of combustion and how to evaluate what makes a good fuel by comparing a variety including biofuel, diesel, LPG, ethanol and hydrogen.