General and Practical Principles in Chemistry
Practical work is central to chemistry. Learning how to be a confident and competent chemist is not only vital for passing the final exam and getting a job but also to avoid poisoning anyone, blowing up the lab or setting yourself on fire. Therefore students are offered plenty of opportunities to put their theoretical knowledge into practice.
There are a least 16 core practicals that students must plan and conduct to investigate things such as how certain elements react with water, heating nitrates or carbonates; how flame colours of s-block elements such as potassium, magnesium and sodium differ; how to prepare iodine from seaweed; how to extract limonene from orange peel; how to set up electrochemical cells; and how to use chromatography (separating components) to identify metals in a ‘silver’ coin or amino acids in a protein. From these practicals students will learn to accurately collect data, analyse and interpret their findings, extrapolate ideas and identify areas for further enquiry.
During these practicals students will also need to think about ethical issues such as sustainability of resources (deciding how much ‘rare’ material to use in an experiment), safe waste disposal (finding a better place than down the sink to pour toxic compounds) and safety in the lab (avoiding accidental fumigation).
Students will be examined on all aspects of the practicals they have conducted, as described above, and also asked to apply what they have learned to other practical scenarios. This includes analysing outcomes, drawing valid conclusions and considering methods and data.
Students will also be asked to talk about how new discoveries, theories or methodologies may be validated (or not) by the scientific community and how they may go on to affect decision making and policy for society.
A level written exam: 2 hrs 30 mins, 120 marks, 40% of overall result.
The paper may include multiple-choice, short open, open-response, calculations and extended writing questions. Some questions will assess conceptual and theoretical understanding of experimental methods.