Recap - Alkanes
The first homologous series is the alkanes. Their names all end in –ane.
The alkanes have many uses:
- methane – (natural gas) cooking, heating
- propane – used in gas cylinders for BBQ etc
- octane – used in petrol for cars
The general formula of the alkanes is \({C_n}{H_{2n + 2}}\). They are insoluble in water.
The names, molecular formula and the structural formula of the first eight alkanes must be learned. Using a mnemonic can make learning the names easier.
| Methane | CH4 | Monsters |
| Ethane | C2H6 | Eat |
| Propane | C3H8 | Pupils |
| Butane | C4H10 | But |
| Pentane | C5H12 | Prefer |
| Hexane | C6H14 | Hairy |
| Heptane | C7H16 | Haggis |
| Octane | C8H18 | Occasionally |
| Methane |
|---|
| CH4 |
| Monsters |
| Ethane |
|---|
| C2H6 |
| Eat |
| Propane |
|---|
| C3H8 |
| Pupils |
| Butane |
|---|
| C4H10 |
| But |
| Pentane |
|---|
| C5H12 |
| Prefer |
| Hexane |
|---|
| C6H14 |
| Hairy |
| Heptane |
|---|
| C7H16 |
| Haggis |
| Octane |
|---|
| C8H18 |
| Occasionally |
General formula, functional group and properties of alkanes.