ALKANES 💥

saturated hydrocarbons

molecules of these compounds contain only single bonds between the carbon atoms in the chain

molecular formula : CnH2n+2

Every organic compound has three different formulae

2. molecular formula

3. structural formula

1. empirical formula

the simplest possible whole-number ratio of the atoms in a compound

represents the actual number of atoms present in the molecules

shows all the atoms in the molecule and how they are bonded together

burning alkanes

features

burn very exothermically

make good fuels

controlling their availability

when they burn in a good supply of air, the products are carbon dioxide and water vapour

methane + oxygen -> carbon dioxide + water CH4(g) + 2O2(g) -> CO2(g) + 2H2O(g)

ethane + oxygen -> carbon dioxide + water 2C2H6(g) + 7O2(g) -> 4CO2(g) + 6H2O(g)

A Homologous Series

have the same general formula

have similar chemical properties

show a gradual increase in physical properties such as melting point and boiling point

Alkane series

butane (C4H10)

pentane (C5H12)

propane (C3H8)

ethane (C2H6)

hexane (C6H14)

methane (CH4)