Isomers of Alcohols

What are Isomers? Isomers have the same molecular formula but different structural formula.

Questions Draw the full structural formula of: Hexan-2-ol Pentan-2-ol Draw as many isomers of hexan-2-ol

Draw the Following Prop-1-ene Methanol Pentan-2-ol Cyclobutane

3-ethyl-2,4-dimethylhexane C H Examples 2,3-dimethylpentane C H C H 2-methylhexane 3-ethyl-2,4-dimethylhexane Formulae from Names H C 5-ethyl-2-methylheptane C H Page 1/2 Worksheets 4,4-dimethyloctane

Uses of Alcohols Solvents Fuels

1. Alcohols as Solvents Short chain alcohols (methanol – butanol) can be used as solvents for perfumes, deodorants, paints and dyes. They evaporate easily to leave the solute. This is useful for cleaning purposes as they can dissolve a variety of compounds and evaporate easily e.g. baby wipes, alcohol hand sanitiser.

2. Alcohols as Fuels Alcohols are very flammable and burn with a clear blue flame. This is an example of complete combustion e.g. Ethanol + Oxygen  Carbon Dioxide and Water CH3OH + 1.5O2  CO2 + 2H2O When alcohols burn they release a large amount of energy (think outcome 1 investigation!)

Methylated Spirits as a Fuel E.g. Methylated spirits (made up of ethanol and methanol) is often used in camping stoves as it is cheap and readily available. Dyes and additives are added to methylated spirits to stop people drinking it.

Ethanol as a Renewable Fuel Fossil fuels such as coal, oil and natural gas are not renewable and cause pollution such as acid rain and global warming. Ethanol is a renewable fuel as it can be produced by fermenting sugars, which can be grown continuously. The ethanol can be used directly as a fuel or mixed with petrol and diesel to produce a fuel blend e.g. Gasohol – this contains 10-20% of ethanol. Countries that have the climate and the space to grow sugar cane are being encouraged to use this as a fuel e.g. Brazil. This is considered renewable as the sugar cane uses up CO2 from the atmosphere to grow which cancels out the CO2 released when the ethanol is burned. This is called a carbon neutral fuel.

Methanol as a Fuel This can be used as a fuel in cars e.g. dragsters and monster trucks. This could be extended for use in more cars across the world.