What content has changed in A-level chemistry?

Most teachers will find the new GCE A-level chemistry specifications for 2008 reassuringly familiar. Much of the previous content has been retained, but some has gone, some material has been reintroduced and there is a smattering of new material. The changes are in three main areas: sustainability and green chemistry; climate change and the atmosphere; and why chemical reactions happen. 

Embracing change

The first two areas reflect the changing nature of the world and the way chemists can make it a better place to live. The last topic aims to ensure that those students who use chemistry as a service subject for other further studies, or who are finishing their chemical studies at A-level, understand the reasons for spontaneous change. 

Sustainability and green chemistry 

All specifications require students to understand atom economy as well as yield when considering chemical reactions. Some also require students to study life-cycle analysis and other elements of sustainability. 

Climate change and the atmosphere 

In all specifications there is a reassuring depth of treatment of the reasons for climate change, which covers the infrared absorption of various greenhouse gases and, in some cases, a requirement to consider carbon capture and storage, the hydrogen economy etc. Most specifications require students to be familiar with the impact of CFCs on the ozone layer and what chemists have done to ensure the effect is reduced by developing alternative refrigerants. Both these areas provide exemplars of 'How science works' in context, and the Royal Society of Chemistry (RSC) will be providing materials to support the teaching of climate change. 

Why chemical reactions happen? 

Specifications cover this material in two ways - either by considering ΔG = ΔH - TS or by considering ΔS total. Teachers of more able students may want to relate ΔG mathematically to equilibrium constants and/or electrode potentials but it appears specifications do not require this approach. Most specifications require students to know how to use electrode potentials to predict the course of chemical reactions. Teachers may want to use the electronic version of the 'anticlockwise rule' in the RSC Electronic data book  to support the teaching of this requirement. Thanks to an education grant from Reckitt Benckiser the RSC will be developing some innovative electronic materials showing how ΔG varies with temperature and how this relationship is used in metal extraction.¹

Assessment

Teachers should be aware of the Qualifications and Curriculum Authority's (QCA) requirement for internal assessment to be done under controlled conditions. It appears that this may well be less burdensome for teachers. 

Although specimen papers are available, these will necessarily have been produced in a hurry and not subject to the normal Question Paper Evaluation Committee review that 'live' papers undergo. The RSC has called on QCA to ensure that the awarding bodies set accessible, rigorous questions that stretch and challenge the most able students and so preserve the standard of A-level chemistry. 

Colin Osborne, RSC education manager schools and colleges.