organic chemistry

• Hydrocarbons: molecules that contain hydrogen and carbon only. 
• Methane: CH4
• Ethane: C2H6
• Propane: C3H8
• Butane: C4H10
• Pentane: C5H12
• Alkanes are ‘saturated compounds’ - every carbon atom has 4 single covalent bonds, there are no double bonds. This means that there is no more space for hydrogen to react with carbon and form more bonds. 
• General Formula: CnH2n+2
• Boiling Point: increases as the length of the chain increases, because there are more intermolecular forces in between that require more energy to overcome as the number increases.

  → methane, ethane, propane and butane therefore have relatively low boiling points and are gases at room temperature, because they have the shortest chains.
• Shorter alkanes are more volatile, meaning that they evaporate more easily because of their low boiling points. Longer alkanes are more viscous, meaning they are sticky and thick, like honey. Shorter alkanes are also more flammable.
• Combustion of Alkanes:

  • One of the main uses of hydrocarbons [e.g. alkanes] is for fuel, because they release a high amount of energy when reacted with oxygen.