Organic Chemistry 0.0 / 5 ? ChemistryOrganic and Green ChemistryGCSEAQA Created by: ChescaCreated on: 16-05-13 17:10 Organic Chemistry Organic molecules contain carbon atoms Methane = 1 carbon atom Ethane = 2 carbon atoms Propane = 3 carbon atoms Single bond between carbon atoms = ALKANE Double bond = ALKENE 1 of 11 Alcohols Have the functional group O-H Functional group = 'family' of organic compounds family with same functional group = homologous series H-C-O-H = Methanol (CH3OH) H-C-C-O-H = Ethanol (C2H5OH) 2 of 11 Carboxylic Acids Ethanoic acid = vinegar Carboxylic acids contain COOH Methanoic acid = CHCOOH Ethanoic acid = C2H3COOH 3 of 11 Esters Esters contain -COO- (Must go in the middle of the molecule) Ethyl Ethanoate: CH3COOC2H5 4 of 11 Properties and uses of alcohols Ethanol is main alcohol in alcoholic drinks made by fermenting sugars from plant material Alcohols dissolve similar substances to water can dissolve other organic compounds useful as solvents (perfumes,aftershaves,mouthwashes) 5 of 11 Combustion Ethanol + Methanol, are used as fuels shows that alcohols are flammable Ethanol burns with a clear blue flame Ethanol + oxygen - carbon dioxide + water 6 of 11 Reaction with Sodium & Oxidation When alcohol added to sodium... sodium 'fizzes', giving off hydrogen gas reaction NOT as vigorous as one with water Oxidation: Combustion can oxidise an alcohol alochol oxidised to carboxylic acid when boiled with acidified potassium dichromate solution (oxidising agent) Ethanol oxidised to ethanoic acid same reaction if ethanol exposed to air microbes produce ethanoic acid from ethanol. 7 of 11 Carboxylic Acids + Esters Carboxylic acids form acidic solutions when dissolved in water Carboxylic acids weak? Carboxylic acids are called 'weak acids'/ Hydrochloric acid is a 'strong acid' pH of 0.1mol/dm3 of hydrochloric acid is 1.0 pH of 0.1 mol/dm3 of ethanoic acid is 2.9 Why if same concentration, is one more acidic? in water all acids ionise (molecules split to form H+ ions) All acidic solutions have H+ ions in common 'Strong acids' ionise completely in solution 'Weak acids' don't completely ionise 8 of 11 Making Esters Carboxylic acids + acids = esters acid (sulfuric acid) acts as a catalyst Esters form are volatile (easily evaporate), sweet/fruity smells :) 9 of 11 Ethanol in drinks Alcohol associated with high blood pressure + heart disease damage to liver! Alcoholics are addicted to ethanol Ethanol used in methylated spirits as solvents Drinking 'meths' = liver failure, blindness, death other chemicals added, makes hard to distill off ethanol 10 of 11 Ethanol and esters in biofuels Ethanol - biofuel = fermenting sugar from crops Biodiesel = plant oils - esters oil broken down into long chain carboxylic acids Reacted with methanol or ethanol with catalyst to make esters used as biodiesel 11 of 11
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