4Crude oil Crude oil is a source of many fuels. It is also the principal feedstock for the manufacture of petroleum-based consumer products because these are compounds of carbon.
5Petrol Petrol can be produced by the reforming of naphtha. Reforming alters the arrangement of atoms in molecules without necessarily changing the number of carbon atoms per molecule.
6As a result of the reforming process, petrol contains branched-chain alkanes, cycloalkanes and aromatic hydrocarbons as well as straight-chain alkanes.Branched-chainhydrocarbonAromatic hydrocarbonCycloalkane
7Any petrol is a blend of hydrocarbons which boil at different temperatures. A winter blend of petrol is different from a summer blend. In winter butane is added to petrol so that it will catch fire more easily.
8EnginesIn a petrol engine, the petrol-air mixture is ignited by a spark.‘Knocking’ is caused by auto-ignition.Auto-ignition is when the petrol-air mix ignites too soon due to the heat from the engine. This makes the engine perform badly.Knocking is when the engine shakes and shudders.
9The tendency of alkanes to auto-ignite used to be reduced by the addition of lead compounds. Unfortunately the lead compounds cause serious environmental problems.
10Unleaded petrol uses components which have a high degree of molecular branching and/or aromatics and/or cycloalkanes to improve the efficiency of burning.
11Alternative fuels Fossil fuels are going to run out in the future. Fuels used produce carbon dioxide, which increases the “greenhouse effect”.We need other fuels which are renewable and non-polluting.
12Sugar cane is a renewable source of ethanol for mixing with petrol. Some biological materials,(i.e. manure and straw) under anaerobic conditions, ferment to produce methane (biogas).Methanol is an alternative fuel to petrol, but it has certain disadvantages, as well as advantages.
13Methanol Almost complete combustion No carcinogens Cheaper than petrol Less explosive than petrolLittle modification to car engineDifficult to mix with petrolVery corrosiveToxicLarger fuel tanks needed.
14Hydrogen could well be the fuel of the future. If water can be electrolysed, using a renewable energy source, such as solar power, hydrogen will be obtained.The hydrogen will burn, producing water, and so will be pollution-free.The problem with hydrogen is storing the gas in large enough quantities.
15Fuels Click to repeat FuelsClick to return to the MenuClick to End
17NomenclatureNomenclature means the way chemical compounds are given names.These names are produced by a special system.
18Naming organic compounds All organic compounds belong to “families” called homologous series.A homologous series is a set of compounds with the same general formula, similar chemical properties and graded physical properties.
19Most homologous series have a special functional group. A functional group is a reactive group of atoms which are attached to the carbon chain.The functional group is the part of the molecule where most reactions take place.
20Functional Groups Functional Group Name of Group Homologous series noneAlkanesDouble bondAlkenesTriple bondAlkynesHydroxylAlkanols (Alcohols)C CC CO H
21Functional Groups Functional Group Name of Group Homologous series CarbonylAlkanals (Aldehydes)Alkanones (Ketones)CarboxylicAlkanoic acidsAmineAminesC HOCOC OHONH2
22The first part of the compound’s name is decided by the number of carbon atoms in the molecule. The second part of the name is decided by the homologous series to which the compound belongs.
23Number of C atomsFirst part of name1meth-5pent-2eth-6hex-3prop-7hept-4but-8oct-
242nd Part of Name Homologous series General Formula Name ending Alkanes CnH 2n+2…aneAlkenesCnH 2n…eneAlkynesCnH 2n-2…yneAlkanolsCnH 2n+1OH…anol
252nd Part of Name Homologous series General Formula Name ending AlkanalsCnH 2n+2…analAlkanonesCnH 2n…anoneAlkanoic acidsCnH 2n-2…anoic acidAminesCnH 2n+1OH…ylamine
26This method works well for straight-chain hydrocarbons. Here is an example: hexaneH H H H H HH C C C C C C HH H H H H H
27We have to add rules to help deal with branched chains. H H H H CH3 HH C C C C C C HH H CH3 H CH3 H
28First draw out the full structure. H H H H CH3 HH C C C C C C HH H CH3 H CH3 H
29Number the atoms in the longest continuous carbon chain. Start at the end nearer most groups.H H H H CH3 HH C C C C C C HH H CH3 H CH3 H654321
30This now gives us the basic name – in this case hexane. H H H H CH3 HH C C C C C C HH H CH3 H CH3 H654321
31You must now identify any side chains. -CH3 is methyl-CH2CH3 is ethyl
32Now identify and count the number and type of side chain. di - shows 2tri – shows 3tetra – shows 4Label the carbon atom(s) they join
33This now gives us the full name: 2,2,4 trimethylhexane. H H H H CH3 HH C C C C C C HH H CH3 H CH3 H654321
34Naming other homologous series works in the same way. With those we start numbering at the end nearer the functional group e.g. this alkene:H H H H CH3 HH C C C C C C HH C2H5 CH3 H
35Number the atoms in the longest carbon chain. H H H H CH3 HH C C C C C C HH C2H5 CH3 H123456
36This now gives us the basic name – in this case hex-2-ene. H H H H CH3 HH C C C C C C HH C2H5 CH3 H123456
37Identifying the side chains gives us the full name: 5,5 dimethy 4 ethyl hex-2-ene.H H H H CH3 HH C C C C C C HH C2H5 CH3 H123456
38We can use the same principles with cyclic hydrocarbons. H HCH HC CC CH HH CH3
40IsomersH C C C C HH H H Hbutane Isomers are compounds with the same molecular formula but different structural formulaeFor example C4H10H C C C HH H HH C HHH H2 methyl propane
41AlcoholsThe alcohols form another homologous series – called the alkanols.We can recognise the alkanols because they contain an OH group.They are given names as if they are substituted alkanes.
423 methyl pentan-2-olH H CH3 H HH C C C C C HH H H OH H12345
43AldehydesThe aldehydes form another homologous series – called the alkanals.We can recognise the alkanals because they contain a carbonyl group at the end of the carbon chain.They are named as if they are substituted alkanes.
443,4 dimethyl pentanalWe don’t need to number the carbonyl group because it must be on the first carbon.H H CH3 H HH C C C C C OH CH3 H H12345
45KetonesThe ketones form another homologous series – called the alkanones.We can recognise the alkanones because they contain a carbonyl group in the middle of the carbon chain.They are named as if they are substituted alkanes.
463,3 dimethyl pentan-2-one H H CH3 H H C C C C C H H H CH3 O H 1 2 3 4 5
47Alkanoic acids The alkanoic acids form another homologous series. Carboxylic acids are used in a variety of ways.
48Alkanoic acidsWe can recognise the alkanoic acids because they contain a COOH group.C OHO
49We can name the alkanoic acids using the principles we have used before. H H CH3 H HH C C C C CH H H H HC OHO
504 methyl hexanoic acidWe don’t need to number the acid group because it must be on the first carbon.H H CH3 H HH C C C C CH H H H H12345C OHO6
51Esters An ester can be identified the ‘-oate’ ending to its name. The ester group is:C OO
52EstersAn ester can be named given the names of the parent alkanol and alkanoic acid.The name also tells us the alkanoic acid and alkanol that are made when the ester is broken down.
57Naming esters Acid name Alkanol name Ester name ethanoic acid methanol methyl ethanoatepropanoic acidethanolethyl propanoatebutanoic acidpropanolpropyl butanoatemethanoic acidbutanolbutyl methanoate
58A typical ester is shown below. H H O H HH C C C O CH H H HC H
59We can identify the part that came from the alkanoic acid – propanoic acid. H H O H HH C C C O CH H H HC H
60We can identify the part that came from the alkanol - ethanol H H O H HH C C C O CH H H HC H
61This gives us the name ethyl propanoate H H O H H H C C C O C H H H H
62Aromatic Hydrocarbons Benzene is the simplest aromatic hydrocarbon.It has the formula C6H6.The benzene molecule has a ring structure.
63Even though benzene would seem to be unsaturated it does not decolourise bromine water. All the bonds in benzene are equivalent to each other – it does not have the usual kind of single and double bonds.
65The bonds in benzene are intermediate between single and double bonds. Their lengths and bond energies are in between those of single and double bonds.
66The stability of the benzene ring is due to the delocalisation of electrons. A benzene ring in which one hydrogen atom has been substituted by another group is known as the phenyl group.The phenyl group has the formula -C6H5.
67Benzene and its related compounds are important as feedstocks. One or more hydrogen atoms of a benzene molecule can be substituted to form a range of consumer products.
68Nomenclature and Structural Formula Click to repeat Nomenclature and Structural FormulaClick to return to the MenuClick to End
70Saturated Hydrocarbons Alkanes and cycloalkanes are saturated hydrocarbons.Saturated hydrocarbons contain only carbon to carbon single covalent bonds.
71Unsaturated Hydrocarbons The alkenes are unsaturated hydrocarbons.Unsaturated hydrocarbons contain at least one carbon to carbon double covalent bond.
72Addition ReactionsAddition reactions take place when atoms, or groups of atoms, add across a carbon to carbon double bond or carbon to carbon triple bond.
73For alkenes the basic reaction is: H H H HC C * * C C* *
74When bromine adds to an alkene we have an addition reaction. C4H8 + Br2 C4H8 Br2H H H HC C Br Br C CBr Br
75The addition reaction between hydrogen chlkoride and an alkene gives the equivalent alkyl chloride. C3H6 + HCl C3H7Clpropene + hydrogen chloride propyl chlorideH H H HC C H Cl C CH Cl
76HalogenoalkanesHalogenoalkanes have properties which make them useful in a variety of consumer products.In the atmosphere, ozone, O3, forms a protective layer which absorbs ultraviolet radiation from the sun.The depletion of the ozone layer is believed to have been caused by the extensive use of certain CFCs (chlorofluorocarbons).
77propene + water propanol C3H6 + H2O C3H7OH The addition reaction between water and an alkene gives the equivalent alkanol.propene + water propanolC3H6 + H2O C3H7OHH H H HC C H2O C CH OH
78Sometimes addition reactions can give two different isomeric products. CH2=CH-CH3HClCH2Cl-CH2-CH3CH3-CHCl-CH3
79EthanolTo meet market demand ethanol is made by means other than fermentation.Industrial ethanol is manufactured by the catalytic hydration of ethene.H H H HH C C H + H2O H C C HH OH
80Ethanol can be converted to ethene by dehydration. This reaction uses aluminium oxide or concentrated sulphuric acid as a catalyst.H H H HH C C OH C C H2O
81For alkynes the reaction takes place in two stages: C C * * C C* ** * * *C C * * C C* *
84With a halogen halide:CH CHHXCHX CH2HXCHX2 CH3CH2X CH2X
85The benzene ring resists any addition reactions. Its delocalised electrons mean that its bonds do not behave like the bonds in an unsaturated compound
86AlcoholsThere are three types of alcohols:PrimarySecondaryTertiary
87Primary AlcoholsPrimary alcohols have at least two hydrogen atoms on the carbon atom carrying the OH group.HC OH
88Secondary AlcoholsSecondary alcohols have one hydrogen atom on the carbon atom carrying the OH group.HC OH
89Tertiary AlcoholsTertiary alcohols have at no hydrogen atoms on the carbon atom carrying the OH group.C OH
90Oxidation and Reduction Oxidation and reduction can be described in terms of loss or gain of electrons.In organic chemistry it is more useful to describe them differently.
91Oxidation is an increase in the oxygen to hydrogen ratio e.g. CH3CH2OH CH3CHO1: :4Reduction is a decrease in the oxygen to hydrogen ratio.CH3CO2H CH3CH2OH2: :6
92Oxidation ReactionsThe simplest oxidation reaction of alcohols is when they are burned in oxygen, giving carbon dioxide and water.Some alcohols can be oxidised to give aldehydes and ketones.
93Primary alcohols can be oxidised in two stages : first to an aldehyde R C O HR C OPrimary alcohol Aldehyde
94Primary alcohols can be oxidised in two stages : first to an aldehyde and then to an alkanoic acid. R C O HR C OPrimary alcohol AldehydeHR C OOHAldehyde Alkanoic Acid
95Secondary alcohols can be oxidised only once: to a ketone R C O HHR C OSecondary alcohol KetoneNo further oxidation is possible
96Tertiary alcohols cannot be oxidised at all. R C O HR**No oxidation is possible
97Aldehydes can be oxidised to give carboxylic (alkanoic) acids while ketones cannot. This can be used as a means of differentiating between aldehydes and ketones.The oxidising agents that are used most often give visible signs of reaction.
108H H OH C C C O HH HH HHO C C HWater is formed from hydrogen of one moleculeand hydroxide from the other.
109H H OH C C C OH HH HC C HH2OWater is formed from hydrogen of one moleculeand hydroxide from the other.
110H H OH C C C OH HH HC C HH2OWater is formed from hydrogen of one moleculeand hydroxide from the other.The remains of the molecules join together
111H H OH C C C OH HH HC C HH2OWater is formed from hydrogen of one moleculeand hydroxide from the other.The remains of the molecules join together
112Hydrolysis ReactionsIn a hydrolysis reaction, a molecule is split up by adding the elements of water.H HOH2O
113The carboxylic acid and the alcohol from which the ester are made can be obtained by hydrolysis. CH3CH2COOCH CH3CH2COOH+ H2O CH3OH
114The formation and hydrolysis of an ester is a reversible reaction. Acid + alkanolEster + waterhydrolysiscondensation
115YieldsIf we write the equation for a reaction we can calculate what mass of product should be produced – the theoretical yield.When we carry out the experiment we can measure the mass of product produced – the actual yield.
116Percentage YieldPercentage yield is the actual yield, expressed as a percentage of the theoretical yield.PercentageYieldActual YieldTheoretical Yield=X1001
118Titanium dioxide, TiO2, is used in the manufacture of white paint Titanium dioxide, TiO2, is used in the manufacture of white paint. It is made from ilmenite, FeTiO3.If 45.1kg of TiO2 is obtained from 100kg of ilmenite, what is the percentage yield of the conversion?FeTiO3 TiO21 mole 1 mole152g 80g1g 80/152g = g100kg kgPercentage yield = x = 85.7%
119Reactions of Carbon Compounds Click to repeat Reactions of Carbon CompoundsClick to return to the MenuClick to End
121Addition Polymerisation Many polymers are made from the small unsaturated molecules, produced by the cracking of oil.They add to each other by opening up their carbon to carbon double bonds.This process is called addition polymerisation.
122Ethene is a starting material of major importance in the petrochemical industry especially for the manufacture of plastics.It is formed by cracking the ethane from the gas fraction or the naphtha fraction from oil.Propene can be formed by cracking the propane from the gas fraction or the naphtha fraction from oil.
123H HC CI*The ethene is attacked by an initiator (I*) which opens up the double bond
124IH HC C*H HC CThe ethene is attacked by an initiator (I*) which opens up the double bondAnother ethene adds on.
125IH HC CC C*H HC CThe ethene is attacked by an initiator (I*) which opens up the double bondAnother ethene adds on.Then another
126IH HC CC C*The ethene is attacked by an initiator (I*) which opens up the double bond….Another ethene adds on.Then another
127Naming polymers The name of the polymer is derived from its monomer. MONOMER POLYMER ***ene poly(***ene)ethene poly(ethene)propene poly(propene)styrene poly(styrene)chloroethene poly(chloroethene)tetrafluoroethene poly(tetrafluoroethene)
128Repeat UnitsYou can look at the structure of an addition polymer and work out its repeat unit and the monomer from which it was formed.The repeat unit of an addition polymer is always only two carbon atoms long.
139Repeat UnitsYou can look at the structure of a condensation polymer and work out its repeat unit and the monomers from which it was formed.
140Polymer-C-(CH2)4-C-N-(CH2)6-N -C-(CH2)4-C-N-(CH2)6-N-O O H H O O H HRepeat Unit-C-(CH2)4-C-N-(CH2)6-N -C-(CH2)4-C-N-(CH2)6-N-O O H H O O H H-C-(CH2)4-C-N-(CH2)6-N-O O H HMonomersHO-C-(CH2)4-C-OHO OH-N-(CH2)6-N-HH Hand
141Polymer-O-C-C6H4-C-O-CH2-CH2 -O-C-C6H4-C-O-CH2-CH2-O O ORepeat Unit-O-C-C6H4-C-O-CH2-CH2 -O-C-C6H4-C-O-CH2-CH2-O O O-O-C-C6H4-C-O-CH2-CH2-O OMonomersH-O-C-C6H4-C-O-HO OandHO-CH2-CH2 -OH
142Condensation Polymers Typical condensation polymers are polyesters and polyamides.Terylene is the brand name for a typical polyester.
143PolyestersAs the name suggests polyesters are polymers which use the ester link.The two monomers which are used are a diacid and a diol.
144The diacid will have a typical structure: C-O-HOH-O-CThe diol will have a typical structure:HOOHThey combine like this:C-O-HOH-O-C
145The diacid will have a typical structure: C-O-HOH-O-CThe diol will have a typical structure:HOOHThey combine like this:C-O-HOH-O-CHOOH
146The diacid will have a typical structure: C-O-HOH-O-CThe diol will have a typical structure:HOOHThey combine like this:C-OOH-O-COHC-O-HOH-O-C
147The diacid will have a typical structure: C-O-HOH-O-CThe diol will have a typical structure:HOOHThey combine like this:C-OOH-O-CC-O-H-CHOOH
148The diacid will have a typical structure: C-O-HOH-O-CThe diol will have a typical structure:HOOHThey combine like this:C-OOH-O-C-COH
149Polyesters are manufactured for use as textile fibres and resins. Polyesters used for textile fibres have a linear structure.Cured polyester resins have a three-dimensional structure. Cross linking between the polyester chains makes the structure much more rigid.
150Amines Amines are a homologous series containing the amine group: N H
151The amide linkThe amide link is formed when an acid and amine join together.N HHHO CO
152The amide linkThe amide link is formed when an acid and amine join together.N HHHO CO
153The amide linkThe amide link is formed when an acid and amine join together.NHCOH2O
154The amide linkThe amide link is formed when an acid and amine join together.NHCOThe amide link
155Polyamides A polyamide is made from a diamine and a diacid: C-O-H H-O-CdiacidH NHN HdiamineThey combine like this:
160Nylon is a typical polyamide. Nylon is a very important engineering plastic.The strength of nylon is caused by hydrogen bonding between the polymer chains.
161Synthesis gasSynthesis gas can be obtained by steam reforming of methane from natural gas.CH4 + H2O CO + 3H2It can also be made by the steam reforming of coal.
162Methanol, used in the production of methanal, is made industrially from synthesis gas. Methanal is an important feedstock in the manufacture of thermosetting plastics.It is used to assist cross-linking so as to make thermosetting plastics and resins.
163New polymersKevlar is an aromatic polyamide which is extremely strong because of the way in which the rigid, linear molecules are packed together.These molecules are held together by hydrogen bonds.Kevlar has many important uses.
164Poly(ethenol) is a plastic which readily dissolves in water Poly(ethenol) is a plastic which readily dissolves in water. It has many important usesIt is made from another plastic by a process known as ester exchange.The percentage of acid groups which have been removed in the production process affects the strengths of the intermolecular forces upon which the solubility depends.
165Poly(ethyne) can be treated to make a polymer which conducts electricity. The conductivity depends on delocalised electrons along the polymer chain.Poly(vinyl carbazole) is a polymer which exhibits photoconductivity and is used in photocopiers.
166Biopol is an example of a biodegradable polymer. The structure of low density polythene can be modified during manufacture to produce a photodegradable polymer.
167Polymers Click to repeat Polymers Click to return to the Menu Click to End
169Fats and OilsNatural fats and oils can be classified according to where they come from:AnimalVegetableMarine
170Fats and oils in the diet supply the body with energy. They are a more concentrated source of energy than carbohydrates.Oils are liquids and fats are solids.Oils have lower melting points than fats.This is because oil molecules have a greater degree of unsaturation.
171Saturated fats:have more regular shapes than unsaturated oils:
172Fat molecules close pack together easily and have a low melting point
173Oil molecules do not close pack together so easily and have a high melting point
174Oils can be converted into hardened fats by adding of hydrogen.
175Oils can be converted into hardened fats by adding of hydrogen.This is how margarine is made
176Fatty acidsFatty acids are straight chain carboxylic acids, containing even numbers of carbon atoms from C4 to C24, primarily C16 and C18.Fatty acids may be saturated or unsaturated.
177Fats and oils are esters. They are made from the triol glycerol (propan-1,2,3-triol)and fatty acids.CH2 OHCH OHglycerolR C OHOfatty acid
178Fats and oils are esters. They are made from the triol glycerol (propan-1,2,3-triol)and fatty acids.CH2 OHCH OHglycerolfatty acidHO C RO
179Three fatty acids form esters with the three OH groups of glycerol.CH2 OHCH OHHO C R1OHO C R2OHO C R3O
180Three fatty acids form esters with the three OH groups of glycerol.C R3OCH2 OCHO C R2C R1
181The hydrolysis of fats and oils produces fatty acids and glycerol in the ratio of three moles of fatty acid to one mole of glycerol.C ROCH2 OCHO C RCH2 OHCH OHR C OH+ 3
182Fats and oilsFats and oils consist largely of mixtures of triglycerides.The three fatty acid molecules combined with each molecule of glycerol need not be the same.Soaps are produced by the hydrolysis of fats and oils.
183Proteins Nitrogen is needed to make protein in plants and animals. Proteins are condensation polymers made up of many amino acid molecules linked together.The structure of the protein is based on the constituent amino acids.
184Amino acidsThese are compounds which contain an amine group and an acid group.N HHRHO C CO H
185There are about 25 essential amino acids. N HHRHO C CO HThere are about 25 essential amino acids.They are different because they have different side groups – shown by “R”.Condensation of amino acids produces the peptide (amide) link.
186The peptide linkThe peptide link is formed when an acid and amine join together. (We have previously called this the amide link.)N HHR1HO C CO HN HHR2HO C CO H
187The peptide linkThe peptide link is formed when an acid and amine join together. (We have previously called this the amide link.)peptidelinkNHR1HO C CO HN HR2C C
188Amino acids polymerising N HHR1HO C CO HN HHR2HO C CO H
189Amino acids polymerising HR1HO C CO HN HR2C CH2ON HHR3HO C CO H
190Amino acids polymerising HR1HO C CO HR2C CH2ON HR3H20N HHR4HO C CO H
191Amino acids polymerising HR1HO C CO HR2C CH2OR3H20N HR4
192Building proteinsProteins specific to the body’s needs are built up within the body.The body cannot make all the amino acids required for body.We need protein in our diet to supply certain amino acids known as essential amino acids.
193DigestionDuring digestion enzymes hydrolyse the proteins in our diet to produce amino acids.The body then builds up the amino acids it needs from those amino acids.
196N HHR4HO C CO HNHR1HO C CO HN HHR2C CO HH2ON HHR3HO C CO H
197N HHR1HO C CO HN HHR4HO C CO HN HHR2C CO HHON HHR3HO C CO H
198HydrolysisThe structural formulae of amino acids obtained from the hydrolysis of proteins can be identified from the structure of a section of the protein as shown in the last few slides.
199Types of proteins Proteins can be classified as fibrous or globular. Fibrous proteins are long and thin and are the major structural materials of animal tissue – muscles, tissues etc.
200Globular proteins have the spiral chains folded into compact units. Globular proteins are involved in the maintenance and regulation of life processes and include enzymes and many hormones, eg insulin and haemoglobin.
201Enzymes Enzymes, such as amylase, are biological catalysts An enzyme will work most efficiently within very specific conditions of temperature and pH.The further conditions are removed from the ideal the less efficiently the enzyme will perform.
202What an enzyme can do is related to its molecular shape. Denaturing of a protein involves physical alteration of the molecules as a result of temperature change or pH change.The ease with which a protein is denatured is related to the fact that enzymes are very sensitive to changes in temperature and pH.
203Natural Products Click to repeat Natural Products Click to return to the MenuClick to End
204Hope you found the revision useful. The EndHope you found the revision useful.Come back soon!!