Organic chemistry is a very important branch of chemistry as judged by the uniqueness of carbon and ubiquitousness of carbon compounds. Together with the basic concepts and knowledge acquired in the junior secondary course, and Topic s V and VI in this curriculum, students build up concepts related to the structural characteristics of some common carbon compounds. Students are also expected to be able to use the systematic and common trivial names of carbon compounds to communicate knowledge and understanding in study and in
daily life.

In this topic, basic concepts of isomerism including structural isomerism, cis-trans isomerism and enantiomerism are introduced. Students will also learn about the chemistry of a number of functional groups. They should be able to give systematic names of alkanes, alkenes, haloalkanes, alcohols, aldehydes and ketones, carboxylic acids, esters, unsubstituted amides and primary amines, with not more than eight carbon atoms in their carbon chains. Through studying the reactions of the functional groups (including the reagents, reaction conditions, products and observations), students will be able to make use of some chemical methods to distinguish different functional groups and to identify unknown carbon compounds. They should also be able to predict major products of reactions between alkenes and hydrogen halides using Markovnikov’s rule. However, the use of reaction mechanisms to explain how carbon compounds react is not expected at this level of study.

Students should also recognise the relationship between different functional groups and be aware of the most important application of organic chemistry, i.e. the synthesis of useful carbon compounds through inter-conversions between different functional groups. To further their understanding of the reactions included in this topic, students should carry out experiments on synthesising simple organic substances. Important organic substances such as aspirin, detergents, nylon and polyesters are discussed in this topic, and students should be able to recognise the structures of these substances. In particular, they should appreciate that the hydrophobic and hydrophilic parts of detergents render the emulsifying and wetting properties of detergents. They should also understand the relation between the cleansing action of soaps and soapless detergents and their structures. In addition, students should recognise that nylon and polyesters are condensation polymers, and write the chemical equations for their formation.