I/GCSE Chemistry- Alkanes

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!

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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