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Chapter 17. Alcohols. contents. You will learn about: Alcohols. alcohols. alcohols. a group of organic compounds with the general formula C n H 2n+1 OH, where n is the number of carbon atoms in one molecule contain the –OH functional group of atoms names end with –ol
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Chapter 17 Alcohols
contents • You will learn about: • Alcohols
alcohols alcohols • a group of organic compounds with the general formula CnH2n+1OH, where n is the number of carbon atoms in one molecule • contain the –OH functional group of atoms • names end with –ol • are covalent molecules • are colourless liquids • have low boiling points • are soluble in water a ball-and-stick model of ethanol, CH3CH2OH
H H C O H H H H H C C O H H H alcohols alcohol homologous series CH3OH Ethanol Ethanol C2H5OH
H H H H C C C O H H H H H H H H O H C C C H C H H H H alcohols alcohol homologous series
alcohols reactions of alcohols: combustion • alcohols burn in air to form carbon dioxide and water ethanol + oxygen carbon dioxide + water
alcohols reactions of alcohols: oxidation • ethanol can also be oxidised by bacteria in air to ethanoic acid • example: beer or wine left exposed to the air for some days turned sour; ethanol oxidised to ethanoic acid ethanol + oxygen ethanoic acid + water
CH2=CH2 + H2O CH3CH2OH glucose ethanol + carbon dioxide alcohols ethanol Ethanol can be made in two ways: • by reacting ethene with steam over a catalyst • by fermentation of sugars or starch with yeast
alcohols ethanol To make a sample of ethanol by fermenting sugar: beaker full of water at 37°C conical flask mixture of yeast and glucose solution limewater fermentation of sugar to make ethanol
alcohols uses of ethanol solvents for paints, varnishes, perfumes alcoholic drinks oxidation ethanol fuel for vehicles making ethanoic acid for preserving food and making esters