Organic Chemistry (Triple Science) Knowledge Organiser PDF

Chemistry Knowledge Fractional Organiser distillation Crude oil is separated into fractions, mostly used as...

Chemistry Knowledge Fractional Organiser distillation Crude oil is separated into fractions, mostly used as fuels or as a feedstock for the chemical industry and Organic Chemistry (Triple used to make materials such as solvents, lubricants, Crude oil Science) polymers, detergents. Finite resource found in rocks formed from ancient Vapourised crude oil Cool biomass, mainly plankton that was buried in mud. is passed into the Mixture of large number of compounds, mainly bottom of the column. hydrocarbons – compounds made of hydrogen and carbon only Vapours rise up the column cooling and Key words Definitions condensing. Hydrocarbon A compound made out of only hydrogen and carbon atoms Hydrocarbons with different boiling Homologous A family of compounds with the same points condense at series general formula and similar chemical different levels. properties. Hot Fractions Mixtures of hydrocarbons with similar numbers of carbon atoms and similar physical properties Viscosity The ability of a liquid to flow. Cracking Long chains → Short Chains (less useful) (more useful) Fuels Alkenes – make polymers Catalytic cracking – High temperature + catalyst Steam cracking – High temperature + steam Alkenes – decolourise bromine water (orange  Chemistry Knowledge Combustion of Organiser hydrocarbons Complete combustion - excess oxygen - carbon dioxide and water formed: Organic Chemistry (Triple e.g. CH4 + 2O2 → CO2 + 2H2O AlkanesScience) Most hydrocarbons in crude oil are part of a homologous Incomplete combustion – limited oxygen – water series called alkanes. always formed along with carbon monoxide and/or carbon General formula CnH2n+2 e.g. C8H18 + 8.5O2 → 8CO + 9H2O e.g. C10H22 + 5.5O2 → 10C + 11H2O A disadvantages of incomplete combustion is less energy is given out so more fuel needed to do the same work. Carbon monoxide is dangerous as it is a toxic gas which is both colourless and odourless (does not smell) - hard Alkenes for us to detect. Functional group: C=C General formula CnH2n Alkanes are saturated hydrocarbons – do not contain double bonds between any of the carbon atoms. ethene propene Boiling points of alkanes The boiling point of alkanes increases as the length of the alkane chain increases due to more intermolecular forces between the molecules. butene pentene Alkenes are unsaturated hydrocarbons – they contain a carbon-carbon double bond.  Chemistry Knowledge Alcohols Functional group: -O-H Organiser Organic Chemistry (Triple Reactions of alkenes Science) Combustion – smoky flames – lots of incomplete combustion – so poor fuels methanol ethanol Addition reaction – with bromine propanol butanol Chlorine and iodine would undergo similar reactions Making ethanol Addition reaction – with water Fermentation – glucose (sugar) + yeast Conditions: warm + anaerobic (no oxygen) alcohol Aqueous solution of ethanol produced – ethanol can be Addition reaction – with hydrogen separated by fractional distillation Ethanol made by fermentation may be carbon neutral – CO2 emitted when it is burnt = CO2 absorbed when plants grow alkane  Chemistry Knowledge Weak acids Organiser Carboxylic acids are weak acids – only slightly dissociated in water Organic Chemistry (Triple Reactions of alcohols CH3COOH ⇌ CH3COO- + H+ Science) pH of solutions 3-6 Combustion – clean flames – very little incomplete combustion – so very good fuels Reactions of carboxylic acids Carbonates – effervescence (bubbling) - CO2 produced Sodium – bubbles of hydrogen gas produced Water – alcohols mix fully with water Alcohols – react to produce esters Oxidising agents – form a carboxylic acid Carboxylic acids Functional group: -COOH ethyl ethanoate methanoic acid ethanoic acid ester group propanoic acid butanoic acid Need to be able to name ethyl ethanoate only