Chemistry A

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This subject looks at theories used by chemists to study chemical bonding, structures and reactions. This course overlaps with physics well and the Quantum Mechanics module in 1A physics gives a good insight into some of the kind of problems approached. A good mathematical ability will help you a lot in this course, however all the mathematics that you will have to use will have been covered in Part 1A Maths. You will have one supervision a week for which you will be required to complete a set of maths based exercises. these are often very difficult so do not be worried if you cannot get the right answer as your supervisor will go through the questions with you but then you must make sure you fully understand the problem as your supervisor will not return to it. Making sure you have the answers to all the supervision questions will be an immensely useful resource come the time to revise. This is one of the most challenging subjects you can take for Part 1B and the workload is heavy and continuous, it is also very important you do not fall behind in your supervisions as much of the work you do builds on what you would have learnt the previous week.

For the Michaelmas and Lent terms you will have one practical class a week (~4 hours long). These classes will alternate each week, one week will be computer exercises where you will model all the theoretical work you have been doing. The other you will acquire practical skills such as using spectrometers, handling a vacuum line and making careful measurements like magnetic moments for which there will be questions and written tasks to complete. Your practical work is marked two weeks after you do the practical and this takes the form of a short interview where a supervisor will question your understanding of the work you have produced.

The first lecture series is Introduction to Quantum Mechanics (12 lectures) which underlies everything else on the course. You are taught the fundamental principles that describe this microscopic world and also how they are applied to the most simple examples. Then you are shown how difficult it becomes when applying these principles to larger systems and taught the approximative methods that are necessary when dealing with anything but the most basic cases. You will see how using these principles to understand electronic interactions leads us to an understanding of chemical bonding and explains certain phenomena, like spin coupling.

For those less confident with their maths during the Michaelmas term there is also a optional mathematics course called Mathematics for Chemists (6 lectures) that revisits topics covered in 1A Maths relevant for solving the problems in the Introduction to Quantum Mechanics Course.

Also in the Michaelmas term are the Molecular Spectroscopy (6 lectures) lectures which actually take place halfway into the Quantum Mechanics course. The course very neatly takes some of the principles you have been learning and applies them to the world of spectroscopy. You learn how to understand spectra and even calculate fundamental molecular parameters from them which you have learnt about in Quantum Mechanics.

Symmetry and Bonding (12 lectures) is the next course and covers the wide ranging applications of symmetry. In the first half of the course the Linear Combination of Atomic Orbitals is applied quantitatively and the language of symmetry is taught in order to simplify these problems. In the second half of the course symmetry is used to analyse bonding and structure in a wide variety of molecules and derive key chemical principles like Huckel’s Rule or the 18 Electron Rule.

The next course is Molecular Energy Levels and Thermodynamics (13 lectures). It uses an understanding of molecular energy levels which can be predicted by Quantum Mechanics and determined experimentally with spectroscopy together with the methods of statistical thermodynamics. The applications include calculating the thermodynamic properties of matter theoretically and producing rate constants for reactions using transition state theory.

The final course is the Electronic Structure and Properties of Solids (16 lectures). This builds on the Quantum Mechanics learnt in the first term enabling you to understand how behaviour of electrons in solids explains their structure and bonding. Two contrasting models of the free electron and the LCAO approach are used as the basis for this whole course. These models are used to explain phenomena such as the bonding and energy bands in solids.

The Natural Sciences Society of St John's College