Hydrocarbons are compounds that consists carbon and hydrogen only. They are the simplest organic compounds. Hydrocarbons, because of their number and variety, are classified into different ways. One way of classifying hydrocarbons is in which way carbon atoms are connected. It can be classified as either a chain aliphatic hydrocarbon or a cyclic hydrocarbon. Chain aliphatic hydrocarbons are compounds that are linked either in a single or branched chain. An example of this is hexane (single chain) and 3-methylhexane (branched). Cyclic hydrocarbons have carbon atoms linked in a closed polygon or a ring and an example is a cyclohexane.
Another way to classify hydrocarbons depends on the type of bonding that exists between the carbons. There are hydrocarbons that contain only carbon-to-carbon single bonds and they are called alkanes. There are also hydrocarbons that contain only carbon-to-carbon single bonds but it is different from alkanes because their carbon atoms are bonded together to form rings. They are called cyclohexanes. Alkanes and cycloalkanes are also known as saturated molecules – containing only carbon-to-carbon single bonds. When we say that a hydrocarbon is saturated, we mean that the carbon is saturated with other atoms. It can only bond to a new atom if it gives up one of the atoms it is already bonded to. Hydrocarbons that contain at least one double carbon bond are the alkenes and those that contain at least one triple carbon bond are called alkynes. These are compounds that are also known as unsaturated molecules.
Lastly, aromatic, is a class of cyclic hydrocarbons that contain a closed loop of electrons.
Generally, hydrocarbons do not mix with polar solvents such as water and ethyl alcohol but they can mix with nonpolar solvents such as ligroin, carbon tetrachloride, or dichloromethane. Crude oil is an example of a hydrocarbon and this product will spread quickly when spilled in water because they are insoluble in it.