You have done the course, done the work, and are outside the exam room; the papers await, the examiners have been appointed, and now all you have to do is to write down what you know in answer to the questions. In the following assume that I am your examiner. For some of you, I might be.

What are you trying to do in the examination? Answer this question before reading on.

Many people will just say 'pass' or 'get an A', or whatever other vague idea comes into their mind. But it's much more precise. Your two principal tasks need to be practised:

• you have to transfer the chemical content of your head into mine with the greatest possible accuracy; like Conrad's character, I cannot know it 'in principle', i.e. unless you choose to tell me;

• you must fight for the BEST answer, not just some near-miss answer that fills up the space available.

These things are important in your everyday work, too, but there's one vital difference. You can talk to your teacher, but you can't talk to the examiner. I can't read your ideas on, say, le Chatelier's Principle or reaction mechanisms, and then ask what you really mean or exactly mean. A friend of mine has often looked at a script at the award and said 'if only I could have been at his shoulder when this was being written I could have nudged him in the right direction.' Or, in other words, examiners often have a gut feeling that the candidate probably knows the answer, but has failed to convince via the only available route - the script. I know that every year I will see scripts from candidates who will have gone home convinced that they have done a good job, but who will be appalled when the results come out. They wrote a lot, and it's nearly there - but it hasn't answered the question. There are some examples of what I mean on ‘The best answer?’ pages.

A module 1 or synoptic topic could involve the balance between hydration and lattice energy to explain solubility. This subject is not easy, but the London syllabus divides it essentially into three points;

• the size of the lattice enthalpy,
• the hydration enthalpy of the ions,
• the extent to which the breakup of the lattice into ions (-DH_latt) is compensated by the hydration enthalpy of the ions.

If a trend in solubility down a group is in question, you have to be clear how the first two factors change down the group. This raises the essential message; once you have learned the detail, and only then, you should reduce your notes to the simplest form to make the scoring points clear. This is a pragmatic response to the exam; it is not the only aim of your studies.

The problem for candidates in questions like this (and you could no doubt think of those similar in principle in other areas of chemistry) is that the process of listing the main points has never been done. They have never been organised, shorn of the particular wording associated with a given question. Thus a candidate may be able to answer a question on this topic if phrased in a way that he has seen before, but not if it is phrased in some other way.