C9.1 - Hydrocarbons

• A hydrocarbon is any compound that is formed from carbon and hydrogen atoms only
• Alkanes are the simplest type of hydrocarbon you can get. They have the general formula CnH2n+2 And have all C-C single bonds.
• The alkanes are a homologous series - a group of organic compounds that react in a similar way
• Alkanes are saturated compounds - each carbon atom forms four single covalent bonds with other carbon atoms
• The first four alkanes: methane, ethane, propane, and butane

  
• Hydrocarbon properties change as the chain gets longer.
• The shorter the carbon chain, the more runny a hydrocarbon is - that is, the less viscous it is. They are also more volatile - they have lower boiling points. They are also more flammable.
• As the length of the carbon chain increases, so does its melting point and boiling point. This means that long chains are solid at room temperature (waxy) or liquid only when heated to high temperatures (oils).
• Longer hydrocarbons are less soluble in water than short ones because their molecules are larger and do not fit into the spaces between water molecules easily.
• Methane has the lowest density of any hydrocarbon gas. It is lighter than air and will rise upwards if released from a container.
• Longer-chain hydrocarbons can be used as lubricants because they do not evaporate easily.
• Crude oil is a fossil fuel. It is formed from the remains of plants and animals, mainly plankton, that died millions of years ago and were buried in mud. Over millions of years with high temperature and pressure, the remains turn to crude oil, which can be drilled up from the rocks where it is found.
• Fossil fuels are non-renewable like coal, oil and natural gas
• Non-renewables are not replenished by nature at the same rate they are consumed