August 21, 2021
This I/GCSE Chemistry blog post will help navigate towards the idea of what alkanes are, let's go!
WHAT ARE ALKANES?
- Alkanes consist of carbon and hydrogen only, so they are also referred to as hydrocarbons. Examples include methane, ethane, propane, butane, octane and dodecane.
- Homologous series= any series of organic compounds which has similar chemical formulae.
- If the alkane has n carbon atoms, it has 2n + 2 hydrogen atoms. The general formula for the whole family is therefore CnH2n + 2.
- The larger the molecule gets, the higher the melting point and boiling point become.
- The greater the number of carbon atoms in the hydrocarbon,
the less volatile it is, the less easily it flows and the less easily it ignites.
- This limits the usefulness of hydrocarbons with large molecules as fuels.
Properties of alkanes:
- all burn in air.
- used extensively as fuels.
- only products of combustion will be carbon dioxide and water (provided there is a good supply of oxygen).
- will produce carbon monoxide if there is a insufficient supply of oxygen.
- are not reactive (will react with bromine in the presence of UV light. The bromine replaces a hydrogen atom in the alkane. This is known as a substitution reaction - CH4 + Br2 = CH3Br + HBr
That is all!
References:
https://www.google.com/url?sa=i&url=https%3A%2F%2Flink.springer.com%2Fchapter%2F10.1007%2F978-3-319-07605-8_1&psig=AOvVaw2XhRFkyDDMSFlDqQtAL1H7&ust=1629648115863000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCLCnzru-wvICFQAAAAAdAAAAABAW
https://www.google.com/url?sa=i&url=https%3A%2F%2Fchemistrypage.in%2Falkane-functional-group-with-examples%2F&psig=AOvVaw2XhRFkyDDMSFlDqQtAL1H7&ust=1629648115863000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCLCnzru-wvICFQAAAAAdAAAAABAj