Carbon compounds

Carbon compounds form the basis of organic chemistry, a branch of chemistry that studies the structure, properties, and reactions of compounds containing carbon. Carbon is unique because it can form four covalent bonds, allowing it to create a vast array of molecules, from simple hydrocarbons like methane to complex polymers and biological molecules. In WJEC GCSE Combined Science, you will focus on the simplest carbon compounds: hydrocarbons, which are compounds made only of carbon and hydrogen. These include alkanes (saturated hydrocarbons) and alkenes (unsaturated hydrocarbons). Understanding carbon compounds is essential because they are the building blocks of fuels, plastics, and many materials we use daily.

This topic also introduces key concepts such as homologous series, functional groups, and isomerism. You will learn how to name and draw the structures of alkanes and alkenes, and how they react in combustion and addition reactions. The topic connects to real-world applications like fractional distillation of crude oil, cracking to produce smaller molecules, and the environmental impact of burning fossil fuels. Mastering carbon compounds lays the groundwork for more advanced chemistry topics and helps you appreciate the chemistry behind everyday products.

In the WJEC exam, you will be expected to recall the general formulas for alkanes (CnH2n+2) and alkenes (CnH2n), identify and name simple members of each series, and describe their chemical reactions. You should also understand the difference between saturated and unsaturated compounds and how to test for unsaturation using bromine water. This topic is a gateway to understanding organic chemistry and its importance in industry and the environment.