The second question on organic chemistry centres on functional groups and the various types of organic compounds such as alcohols, aldehydes, ketones, carboxylic acids and esters. Type and mechanism of reaction are of particular importance. The main reactions types and mechanisms to be known are substitution, addition, elimination and esterification and a popular question on the paper is one constituting a reaction scheme relating several types of organic compounds about which you are asked conditions and mechanism of conversion. It is important, in describing any mechanism, to be able to back it up with whatever evidence there is available for that mechanism.

Questions 8 & 9 are the questions that are likely to be based on equilibrium and rates of reaction, but the position or appearance of these questions can vary, as can be seen from the papers available. Other topics that have been presented for examination in this area of the paper include water, acids, bases, pH, indicators and redox reactions.

With regard to questions on equilibrium, make sure you understand reversible and dynamic equilibrium and the significance of the magnitude of an equilibrium constant. Be able to use Le Chatelier's principle to predict the effect of varying conditions in equilibrium reactions, practise the writing of equilibrium constant expressions (equilibrium law) and make sure, if given concentrations, you can calculate equilibrium constants or, if given an equilibrium constant, you can calculate concentrations. Be mindful here of the possible inclusion of a pH calculation in this question, particularly in relation to the dissociation of ethanoic acid.

On rates of reaction, make sure you know the factors that affect the rate of a reaction and the experiments that illustrate these. Be able to calculate average rates and instantaneous rates and know the difference between them. Catalysis is important here; make sure you know the types and mechanisms of catalysis, the catalytic converter and the effect of a catalyst on the activation energy of a reaction. In this regard, you should ensure that you can draw energy profile diagrams both for exothermic and endothermic reactions.

Questions 10 & 11 are both three-part questions of which you must answer two. These questions are generally a mixed bag and mop up much of the material that has not been examined as full questions on the rest of the paper. Popular topics in these questions are stoichiometry and radioactivity, but these questions are really the anything goes type with the exception of course of question 11 where the option question usually appears. There are two options given (usually as part c, A and B) and, if you are answering this question, you can, if you so wish, choose one but only one of the options.

General advice

• Target your questions and know the questions you want to answer prior to going into the exam.
• Always have a couple of extra questions prepared in case any of your targeted questions do not appear.
• When the exam starts, as soon as it starts, write down the formulae of any compounds, together with any equations you find difficult to remember.
• It is a good idea to aim to answer all three questions of Section A, leaving only five questions to be attempted in Section B.
• The options question is not particularly good value for the amount to be learned in order to answer it and you can avoid it if you so wish, taking the other two parts of question 11 instead. That is, of course, if you are attempting question 11 in the first place.
• Attempt all eight questions you are required to attempt.
• Keep your answers short and to the point but at the same time do not spare the detail.

The very best of luck.
Orla