Chemistry

Chemistry is a core subject: every KGS student studies it to GCSE with around a third of Lower Sixth students choosing to study the A Level. Entrusted with this time, one of the most important things the Chemistry Department can do is open students’ eyes to the way chemistry has shaped the development of human civilisation. The discovery in the Middle East (around 3000 BC) that included fragments of green rock exposing shiny orange copper in the ashes of a fire brought man out of the Stone Age. Our ability to make useful things from otherwise useless things has continued to advance our civilisation ever since.

Metals rightly form a significant part of the curriculum and students recreate early smelting of copper to develop an understanding of methods for extracting other metals based on their reactivity. They also learn how to protect metals from corrosion and how the properties of different metals are harnessed for their applications. Upper Sixth students study the properties and reactions of the transition metals as their final topic.

Global warming is perhaps the most pressing issue of our age and the scientific consensus that this warming is anthropogenic is prompting major shifts in policy and governments’ spending.

In the Third Year, students study the composition of the atmosphere, including the effects of increased carbon dioxide, whilst A Level students are able to understand the phenomenon in more depth. As the world continues to discuss reducing emissions from burning fossil fuels, it is worth remembering just how valuable crude oil is to our society.

In the Fourth Year, students spend several weeks studying the extraction of crude oil as part of their IGCSE course, building on what they learnt about separating techniques in the First and Second Years. They learn what happens in combustion reactions and the dangers of incomplete combustion (forming colourless, odourless and highly toxic carbon monoxide gas). Later, they calculate the energy given out by fuels as part of the Energetics topic and then begin to explore Organic Chemistry (the chemistry of carbon), which is wholly based on materials that can be obtained from oil. Indeed, a case can be made that oil is far too precious a resource to continue to waste by burning it! Consider aspirin and paracetamol as everyday pain killers: both are made from benzene, which is obtained by the fractional distillation of crude oil.

Aspirin is made in a multi-step process, with benzene converted to cumene, then phenol, then 2-hydroxybenzoic acid, and finally to aspirin. Upper Sixth students have the opportunity to carry out the final step in this process as part of their A Level studies, learning first-hand that the amount of product produced in a reaction is not always as large as might be hoped.

The production of sulphuric acid (from sulphur, air and water) is another important industrial process, with the acid finding use in a huge range of processes, including the production of medicines, paints and fertilisers. Students meet acids from Second Year, with A Level chemists introduced to a more mathematical treatment in the Upper Sixth, enabling them to understand a much wider range of phenomena.

These are just a few examples of how the chemistry that KGS students learn enables them to understand the world around them and the way it enables humans to manipulate and adapt the resources of the planet. In developing an appreciation of the impact this has on the environment, they are equipped to participate thoughtfully in the debates of their generation. Dr L Winning, Head of Chemistry