It’s always important to start at the beginning! There is so much terminology in organic chemistry, from the naming of molecules, their classification, arranging them into families with similar properties, the names of different reactions and in how these reactions happen.
Hydrocarbons can be split into 3 families of molecules:
- Aromatic hydrocarbons are based on benzene, C6H6. They contain ring systems of delocalised electrons which confer stability to the molecule and govern the way in which it reacts.
- Aliphatic hydrocarbons are straight chain or branched chain molecules without extensive delocalised systems of electrons. There are many homologous series of aliphatic hydrocarbons, with each series sharing a common functional group that heavily influences its chemical properties e.g. alkenes, ketones, carboxylic acids.
The functional group for each homologous series is marked in orange – notice how common the carbonyl group, C=O is.
- Alicyclic hydrocarbons are cyclic versions of aliphatic molecules e.g. cyclohexane, cyclopentan-1-ol, cyclohept-1-ene.
Saturated hydrocarbons only contain single C-C bonds e.g. alkanes and unsaturated hydrocarbons contain at least one C=C double bond e.g. alkenes.
There are also different types of formula. You will be familiar with the structural and displayed formulae illustrated above, but you also need to be confident in drawing and working with skeletal formulae for organic molecules (it’s basically shorthand). The super-quick video below explains all 🙃.