CHAPTER 2 : CARBON COMPOUNDS Carbon compounds can be classified as organic carbon compounds and inorganic carbon compounds.Hydrocarbon compounds are organic compounds that contain only carbon and hydrogen hy drogen elements that bond together by covalent bonds.There are two types of hydrocarbon compounds which are saturated hydrocarbon compounds and unsaturated hydrocarbon compounds.
Table 11.1 Comparison between between organic and inorganic carbon compounds compounds
Table 11.2 Comparison between saturated and unsaturated hydrocarbon compounds
Table 11.3 Functional groups groups of several homologous series
Table 11.4 General formulae of homologous series. Alkane is a saturated hydrocarbon compound with a general formula of CnH2n+2 whereby n = 1,2,3,...All alkanes burn completely, in excess
oxygen,O2, to form carbon dioxide,C dioxide,CO O2,and water,H2O.When a mixture of alkane and halogen such as chlorine,CI2 and bromine,Br2, is exposed to sunlight or ultraviolet rays,the hydrogenatoms in the alkane moleciles are replaced by the halogen atoms.Ther atoms.Therefore,a efore,a substitution reactions occurs.
Table 11.5 Molecular formulae formulae for the first first ten alkane members
Table 11.6 Nomenclature of the first ten alkane members Long-chained alkanes can be broken into shorter-chained alkanes and alkenes via the industrial process p rocess of cracking.Alkane is an unsaturated
hydrocarbon compound that has a double bond between two carbons atoms,C=C.
Table 11.7 Structural formulae of the first ten members of straight-chain alkanes Alkenes can be represented by a general formula of C nH2n whereby n = 2,3,4...An addition reaction(bromination) occurs when an alkene is shaken with bromine water.
Table 11.8 Nomenclature of the first nine nine members of alkenes
Table 11.9 Guidelines when drawing the structural formula of straight-chain alkenes. When a mixture of alkene gas and a nd hydrogen,H2,gas is passed over a nickel (or platinum) catalyst that is heated at 180ºC,an addition reaction(hydrogenation) reaction(hydrogenation) occurs.
When a mixture of alkene gas and a nd steam,H2O, is passed throygh a catalyst of phosphoric acid,H3PO4, at a temperature of 300ºC,and at a pressure of 60 atmospheres,an atmospheres ,an addition reaction(hydration) occurs.
Table 11.10 Physical properties properties of alkenes. An addition reaction occurs when a mixture of alkene gas and hydrogen hy drogen halide,such as hydrogen bromide,HBr,reacts bromide,HBr,reacts at room temperature.When an alkene is shaken with acidified potassium manganate(VII),KMnO manganat e(VII),KMnO4, solution,an addition reaction(oxidation) occurs.
Table 11.11 Similar physical properties of alkanes and alkenes Alkene molecules can combine to produce polymer through the addition reactions.Both alkane and alkene are insoluble in water, less dense than water, and burns in excess oxygen to produce carbon dioxide and water.Hexene,C6H12,burns with a more sooty flame comparedto hexane,C6H14 . Isomerism is an occurance when two or more compound molecules have the
same molecular formula but different structural formulae.Alkane shows isomerism that begins from butane while alkene shows isomerism that begins from butene.
Table 11.12 Alkyl group that that is derived derived from a matching alkane name Alcohol is an organic compound that has a hydroxyl,-OH,fuctional group.Alcohol can be represented by a general formula of C nH2n+1OH whereby n =1,2,3...Alcohol shows isomerism beginning from proponal.
Table 11.13 Molecular formulae formulae of the first first ten alcohol members
Table 11.14 Nomenclature of of the first ten alcohol members. In industry,ethanol is produced from the addition reaction or the hydration of ethene.The mixture of ethene vapour and steam is passed through a catalyst of phosphoric acid, H3PO4 at a temperature of 300ºC and is compressed at a pressure of 60 atmospheres.
Ethanol can be produced through the fermentation process on a carbohydrate source in the laboratory.Fermentation is the decomposition process of carbohydrates to form ethanol (alcohol) and carbon dioxide by yeast. Distillation process needs to be carried ca rried out the fermantation process.Ethanol is a liquid that th at is colourless at room temperature, neutral,pungent,easily vaporised,flammable,and can be mixed with water. Ethanol can be changed to ethene through the dehydration reaction.Ethanol can be changed to ethanoic acid when heated with acidified potassium dichromate(VI) solution.An oxidation reaction occurs.
Table 11.15 Chemical properties of ethanol and other alcohol members When ethanol is heated under reflux with an organic acid like ethanoic acid,CH3COOH and concentrated sulphuric acid which acts as a catalyst,an cataly st,an esterification reaction occurs. Ethanol reacts with reactive metals such as sodium and potassium to to
release hydrogen.Alcohol can be used as fuel, in the manufacture of medicine,cosmetics and artificial food flavourings.Excessive consumption of alcohol (ethanol) can affect one's health.
Table 11.16 Some uses of alcohol Carboxylic acid is a homologous series that has a general g eneral formula of CnH2n+1COOH,whereby n=0,1,2,3,....Each carboxylic acid member contains a functional group called the carboxyl,-COOH,group.
Ethanoic acid can be prepared in the laboratory by heating under reflux a mixture of ethanol and acidified a cidified potassium dichromate(VI) solution.Ethanoic acid is a colourless liquid at room temperature,dissilves temperature,dissilves in water,and changes damp blue litmus to red (ph<7). Ethanoic acid reacts with a base to produce salt and a nd water .Ethanoic acid reacts with metals carbonate to produce salt, water and carbon dioxide.Ethanoic acid reacts with reactive metals such as zinc and magnesium to produce salt and releases hydeogen gas. Ethanoic acid reacts with alcohol and concentrated sulphuric acid which acts as catalyst to produce p roduce ester and water.Carboxylic acid can be used to make food flavourings and food preservatives. Ester has a general formula of CnH2n+1 COOCmH2m+1 whereby n=0,1,2,...and m=1,2,3.. Each ester has a functional group -COO-.Ester can be prepared through the reaction of carboxylic acid and alcohol with concentrated sulphuric acid as a catalyst.Ester has a pleasant fruity smell, is insoluble in water and easily vaporises.Ester is used as food flavourings,in making cosmetics and as perfume.
Table 11.17 Anions of carboxylic acid salts Fats and oil are natural esters formed from the reaction between between fatty acids and glycerol.Fatty acids are carboxylic acids that have ha ve a long carbon atom chain.The functional group of fatty acids is -COOH.Fats can be classified as saturated and unsaturated fats.
Table 11.18 Importance of oils and fats for the body processes
Saturated fats is a type of fat produced fromthe reaction between saturated fatty acids and glycerol.An example of saturated fatty acids are palmitic acid,CH3(CH2)16COOH.Unsaturated fat is a type of fat produced p roduced from the reaction between unsaturated fatty acids and glycerol.
The structure of oil palm fruit Examples of unsaturated fatty acids are, linoleic acid, CH3(CH2)4CH=CH2CH=CH(CH2)7 COOH and oleic acids,CH3(CH2)7 CH=CH(CH2)7COOH.Unsaturated fats from vegetable oils such as palm oil, can be changed c hanged to saturated fats such as margerine through the hydrogenation process. A big portion of the palm oil comes from oil extracted from its mesocarp. Natural rubber is soft,elastic and non-heat resistant.Rubber particles are made of rubber molecules that are covered with a protein membrane that has negative charges on its surface.
Structure of vulcanised rubber
Rubber particles are made of rubber molecules that are covered with a protein membrane that has negative charges on its surface.Acids have hydrogen ions,H+, with a positive p ositive charge of the membrane which causes the coagulation of latex.
Sequence of changing unvulcanised rubber to vulcanised rubber
Coagulation of latex can be prevented by adding ammonia solution.The vulcanisation process is a process p rocess where sulphur is added to natural rubber to increase its toughness,elasticity and heat resistance.
