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Unit 1 Section (a) – Reaction Rates 1. The rate of a reaction can be followed by measuring changes in concentration, mass or volume. Change in …………………………, ……………………….. or …………………………. Rate = ………………………………… taken Units are mol l-1 s-1 (for concentration change), ………………. (for mass change), …………………… (for volume change) 2. The rate of a reaction is proportional to 1/........................................ (units s-1). 3. Reaction rate increases as the concentration of a reactant......................................... As the concentration of a reactant increases the number of collisions between reactant particles ............................................ . 4. Reaction rate increases as the particle size of solid reactants ......................................... The smaller the particle size the ....................................... the surface area of the solid. The bigger the surface area the ................................ collisions there are between reactant particles. 5. Reaction rate increases as the temperature at which the reaction is carried out ............................... Temperature is a measure of the average ............................................. energy of the particles of a substance. The higher the kinetic energy of the particles the ............................................ the number of collisions between reactant particles. 6. The .......................................... energy (EA) is the minimum kinetic energy required by colliding particles before reaction will occur. Increasing the temperature ......................................... the number of particles which possess the .................................................. energy (E A) and so increases the rate of the reaction. A ............................... increase in temperature can give a large increase in reaction rate. 7. With some chemical reactions light energy can be used to increase the number of particles with the necessary activation energy. One such reaction is ........................................................... in which green plants use light energy to make starch. 8. From a balanced chemical equation the amount of a reactant in excess can be calculated. (See separate booklet on Higher Chemistry calculations). 9. A .................................................... catalyst is in the same physical state as the reactants. A ..................................................... catalyst is in a different physical state to at least one of the reactants. 10. Heterogeneous catalysts work by adsorbing a reactant onto the surface of the catalyst. The reactant that is absorbed forms ........................ bonds with the active site on the catalysts surface. The reactant adsorbed and the .......................... site are complementary in size and shape. 1 11. The surface activity of a catalyst can be ............................................. by a catalyst poison. For example, cars fitted with catalytic converters have to use .......................................... petrol as any ....................... would poison the catalyst. The catalytic converter converts harmful carbon monoxide and oxides of nitrogen into ..................................................................... and ......................................................... 12. The aluminium oxide catalyst used in cracking long chain hydrocarbons often gets covered in soot and so the soot has to be .......................... off and the catalyst regenerated. 13. ...................................... catalyse the reactions taking place inside the cells of living plants and animals. 14. ..................................... are also used to catalyse many industrial processes. For example, zymase is used to catalyse the fermentation of sugar into .................................................. Section (b) – Enthalpy 1. In an ............................................... reaction heat energy is released to the surroundings. In an ............................................... reaction heat energy is absorbed from the surroundings. 2. In an exothermic reaction the reactants have ........................... stored energy than the products. In an endothermic reaction the reactants have ........................... stored energy than the products. 3. A potential energy diagram can be used to show the energy stored in both reactants and products. The enthalpy change (H) for the reaction is given by Hproducts - .............................................. The enthalpy change has a negative value in an ............................................... reaction and a positive value in an .................................................... reaction. exothermic reaction 4. The activated ................................... is an unstable arrangement of atoms formed at the maximum of the potential energy barrier during a reaction . 5. The ........................................... ................................... (E A) is the minimum energy required by the reactant particles in order to form the activated complex. 6. A catalyst speeds up a reaction by providing an alternative reaction pathway with a ............................... activation energy. 7. The enthalpy of ...................................................... is the amount of heat energy give out when one ............ of a substance is completely burned in oxygen. 8. The enthalpy of ...................................................... is the enthalpy change when one ............of a substance is dissolved in water. 9. The enthalpy of ........................................................ is the mount of heat energy give out when one ............ of water is formed in the neutralisation of an acid. 10. Enthalpy change can be calculated using the relationship H= - cmT where c is the ..................................................................................... of the substance (usually water with a value of 4.18 kJ kg-1 oC-1) m is the mass in ................................................ (kg) of the solution being heated. T is the temperature change (in ............). 2 Section (c) – Patterns in the Periodic Table. 1. The Modern day Periodic Table is based on the work of the Russian chemist ............................................. who arranged the elements in order of increasing .................................... mass and left spaces for yet to be .................................................... elements. The present day Periodic Table actually arranges the elements in order of increasing atomic number (the number of .............................. in the nucleus of an atom). 2. The covalent radius of the elements ................................................ from left to right across a period and .................................................. from top to bottom within a group. 3. The .................................................. in covalent radius from left to right across a group is due to an ................................................. in the number of protons (positive charges) in the nucleus attracting the electron energy levels ......................................... to the nucleus. 4. The .................................................. in covalent radius from top to bottom in a group is due to an .............................................. in the number of occupied electron energy levels as we go down the group. Each new energy level is ..................................... away from the nucleus making the atom ............................. in size. 5. The first ........................................................ energy is the amount of energy that has to be supplied to remove one mole of electrons from one mole of neutral atoms in the gas state. ie for sodium Na(g) ................ + ........... H= .................... kJ mol-1 (data booklet page 10) 6. The second ...................................... energy is the amount of energy to remove one mole of electrons from one mole of +1 ions in the gas sate. + ie for sodium Na (g) ................... + ...................... H= .................. kJ mol-1 (data booklet page 10) 7. The second ionisation energy is higher than the first due to the electron having to be removed from a ......................... ion rather from a .......................... atom. 8. The first ionisation energy ..................................... from left to right across a group due to the increasing number of ................................. in the nucleus attracting the electrons more ........................... This increased attraction means that more energy has to be supplied to remove an electron from the atom. 9. The first ionisation energy ............................... from top to bottom within a group due to the increasing number of occupied electron ................................... .......................................... Each new energy level that is occupied is ........................... away from the nucleus. Each new energy level provides additional screening and so it requires ............................. energy to remove an electron. 10. Atoms of different atoms have different attractions for bonding electrons. The .................................................................. value is a measure of the attraction that an atom has for electrons it shares with other atoms. 11. The higher the electronegativity value of an atom the more ...................................... it attracts bonding electrons towards itself. 3 12. Electronegativity values ..................................... from left to right across a period. This is due to an increase in the number of ................................ in the nucleus of the atoms attracting the shared electrons in the bond more strongly. 13. Electronegativity value ...................................... from top to bottom within a group. This is due to the greater ..................................... effect on more occupied electron energy levels. Section (d) - Bonding, structure and properties of the first 20 elements. 1. Metallic bonding is an electrostatic attraction between the ................................charged nucleus and the delocalised outer .................................................. 2. Atoms of non-metal elements bond together by sharing electrons – this type of bond is known as a ......................................... bond. In a ..................................... bond the atoms are held together by an electrostatic attraction between the ........................................ charged shared electrons and the ............................................ charged nuclei. 3, Ionic bonding usually occurs between metal and ........................................ atoms. Ionic bonding is an electrostatic attraction between the .......................................... charged metal ions and the ........................................... charged non-metal ions. 4. ............... der ........................ forces are weak forces of attraction that exists between covalent molecules and also between the atoms of ............................. gases (group 8). .................... der ................... forces are much .................................. than all other types of bonding. 5. Van der Waals forces are caused by small electrostatic attractions between ...................................... dipoles created in atoms by an uneven distribution of electrons in the electron cloud round an atom. 6. Van der Waals forces ................................... in strength as we go down groups 5, 6 7 and 8. Bigger atoms have more electrons and so the size of the temporary dipoles ..................................... as we go down the group. 7. A molecule is described as being polar if the it has a ......................................................... dipole. eg hydrogen chloride +H-Cl-. 8. The electrostatic attraction between molecules with permanent dipoles are .................................... than the weak van der Waals forces between molecules with .................................................. dipoles. 9. Symmetrical molecules with polar bonds are themselves ................................................ – the symmetry cancels out the polarity of the bonds. For example, +O=C+=O- is a non-polar molecule as it has a ........................................ shape. 10. Bonds in which a hydrogen atom are bonded to a much more electronegative element are very strongly polar. The elements which are much more electronegative are nitrogen, ........................, ....................................... and .......................................... Hydrogen bonds are .................................... forces of attraction between these highly polar molecules eg +H-F+H-F hydrogen bonds). 11. Hydrogen bonds are ............................ than other forms of permanent dipole attractions but they are weaker than covalent bonds. 4 12. A metallic structure consists of a giant .................................... of positive ions surrounded by ...................................................... outer electrons. - + delocalised outer ............................... - - + + + - - + + + + + + - - - - + + + + + - - - + - - lattice of ......................... charged nuclei + + - - 13. A covalent molecular structure consists of discrete molecules with ............................... bonds between the atoms inside the molecule and weak ...................... ..................... ............................. for ces between the molecules. H eg covalent bond H H van der Waals force H 14. A covalent network structure consists of a giant ........................................ of covalently bonded atoms. covalent bond eg diamond 15. An ionic structure consists of a giant .................................... of oppositely ...................................... ions. eg sodium chloride 16. A monatomic structure consists of individual atoms with weak .................... ................. ..................... forces between the atoms. He van der Waals force He 17. The first 20 elements in the Periodic Table can be categorised according to bonding and structure. Metallic (Li, Be, .........., ............, .............., ..............., ................, ) Covalent molecular gases (H2, N2, ............, ................, .................) Covalent molecular solids (P4, ................ and fullerines C60) Covalent networks (B, ........... and .............) Monatomic (He, Ne, .........., ............., ................, .................) 5 Section (e) – Bonding and structure of compounds 1. Compounds adopt one of three different structures. Covalent molecular – discrete molecules with ................................ bonds between the atoms inside the molecule and weak ................ ................. ..................... forces between the molecules. eg methane (CH4) .................................................... bond between atoms within the molecule weak van der Waals forces ....................... the molecules Covalent network – a giant ............................ of covalently bonded atoms. eg silicon dioxide Ionic - a giant ............................... of oppositely charged ions eg sodium chloride Section (f) – Properties associated with bonding 1. The melting and boiling points of polar substances is ................................... than the melting and boiling points of non-polar substances with similar molecular mass. 2. Ionic and polar substances tend to be ........................................ in polar solvents such as water. Non-polar substances tend to be .......................................... in polar solvents such as water 3. Water (H2O), ammonia (............) and hydrogen fluoride (...........) have ................................... than expected boiling points due to ............................................ bonding between the polar molecules. 4. Hydrogen bonding between water molecules results in ice having a very open structure. this results in ice having a ....................................... density than liquid water and so ice ..................... on water. 5. Diamond is a very .................... and strong substance due to its giant ....................................... structure. In diamond every carbon atoms is bonded to .................. other atoms. This means that all 4 electrons in a carbon atoms ............................ shell are bonded and so carbon does not ............................................ electricity. 6 6. In graphite the carbon atoms are arranged in ........................................ with weak van der Waals forces between the layers. This makes graphite ......................... and slippery. As only 3 of the 4 electrons in the outer energy level are shared there are ........................................... electrons which makes it an electrical ............................................ 7. Silicon carbide (SiC) has a giant covalent ....................................... structure. This makes silicon carbide very ........................ and strong. It is used in cutting and grinding tools. Section (g) – The Mole 1. One mole of a substance contains 6.02 x 1023 formula units of the substance. For example. a) 1 mole of carbon (C) contains ............................................................ carbon atoms. b) 1 mole of sulphur dioxide (SO2) contains 6.02 x 1023 sulphur dioxide ............................................... c) 1 mole of sodium chloride (Na+Cl-) contains ................................................. Na +Cl- formula units. 2. The Avogadro Constant (L) has a value of ........................................... particles per mole. 3. The number of moles of a solid can be calculated using the relationship where m = .............................. of the substance n = number of .................. of the substance m n gfm gfm = ................... ........................ mass of the substance 4. The number of moles of a substance in solution can be calculated using the relationship where n = number of .................. of the substance n C V(l) C = the ................................ of the solution V(l) = the ............................. of the solution in litres 5. One mole of a gas occupies the ....................... volume at the same temperature and pressure. The volume of gas that one mole occupies is called the .............................. volume of the gas. 6. The volumes of reactants and product gases can be calculated using the number of moles of each reactant and product as shown in balanced equation. There are many different types of calculation using the mole, Avogadro Constant and molar volumers of a gas (See separate booklet on Higher Chemistry calculations). 7 Unit 2 Section (a) – Fuels 1. Petrol can be produced by the ........................................... of the naphtha fraction from crude oil. 2. ........................................... alters the arrangement of atoms in a molecule without necessarily changing the ..................................... of carbon atoms in the molecule. 3. As a result of reforming many straight chain molecules in the naphtha fraction are changed into ........................................... chain , aromatic and .......................................... molecules. 4. ‘Knocking’ is caused by petrol auto-igniting. Straight chain hydrocarbon molecules are ................... likely to auto-ignite than branched chain, ....................................... or ................................... hydrocarbon compounds. 5. Lead compounds used to be added to petrol to prevent ............................................. 6. Unleaded petrol contains has a ..................................... proportion of branched chain, aromatic and cyclic compounds than leaded petrol. 7. In petrol engines the mixture of petrol and air is ignited by a ............................ from a ................... plug. 8. Petrol is a blend of hydrocarbons of different volatilities to suit different conditions. In winter more of the ............................ volatile smaller molecules are used to prevent the petrol from ....................................... in winter. Section (b) – Alternative fuels 1. Ethanol can be produced by the ........................................... of sugar from sugar cane. This makes ethanol a .......................................... source of energy. 2. The use of methanol as an alternative to petrol has both advantages and disadvantages. Some advantages are that it is a ................................. burning fuel and it does not contain the very harmful and carcinogenic compounds such as .................................. found in unleaded petrol. Some disdvantages are it is a very .......................... compound and it absorbs water so the risk of .................................. of the metal components in a car engine is increased. 3. ............................ is a renewable fuel produced when biological materials undergo anaerobic respiration. ............................... contains a mixture of methane and carbon dioxide. 4. Hydrogen is a possible fuel for the future. Hydrogen can be produced by the ........................................ of water – hydrogen forming at the ...................................... electrode. If the electricity for the .................................................. can be produced fron renewable and non-polluting sources such as wind power, ................................... or ...................................................... the hydrogen will be a much more environmentally fuel than fossil fuels. 5. The burning of hydrogen produces only ......................................... Replacing petrol with hydrogen will, therefore, reduce the amount of .................................... ........................................... in the atmosphere and reduce the effects of Global Warming. 8 Section (c) – Nomenclature and structural formulae. 1. Alkanes are saturated hydrocarbons having the general formula ................................... Saturated hydrocarbons contain only .................................... covalent bonds. 2. Cycloalkanes are saturated hydrocarbons having the general formula ................................... Cycloalkanes have a ........................... ring of carbon atoms 3. Alkenes are unsaturated hydrocarbons having the general formula ................................... Unsaturated hydrocarbons contain a carbon to carbon .......................... covalent bond. 4. Alkynes are unsaturated hydrocarbons having the general formula ................................... Alkynes contain a carbon to carbon .......................... covalent bond. 5. Alcohols contain the ......................................... (-OH) functional group and have names that end in –ol. The general formula for straight chain alcohols (alkanols) is ........................................... 6. Aldehydes and ketones contain the .......................................... (-C=O) functional group. In aldehydes the ................................. (-C=O) group is on the ................ of the carbon chain. In ketones the .................................... (-C=O) group is not on the ..................... of the carbon chain. eg H H H C C H H O H H and C H C C H O C H H H is the .............................. called ............................. and this is the ............................. called ........................... 7. Aldehydes have a name ending in ..................... while ketones have a name ending in ........................ 8. Carboxylic acids contain the ......................................... ( -COOH) functional group. Carboxylic acids have a name ending of -......................... acid. O H H H eg H C C C H H H C O H is called ..................................................... acid. 9. You must be able to give the systematic names, molecular formulae, condensed and structural formula of the alkanes, cycloalkanes, alkenes, alkynes, alcohols, aldehydes, ketones and carboxylic acids with up to 8 carbon atoms per molecule. 10. Esters contain the ester functional group ( .....................) and have a name ending of –oate. The first part of an esters name comes from the parent alchol eg ethanol gives an ....................... ester. The second part of the ester name comes from the parent carboxylic acid eg propanoic acid gives a ......................................... ester. eg H H H C C H H O O H ....................................... + H O H C H + ............................... acid --> 9 H H C C H H O O + C H O H ............................................. + water H 11. Aromatic compounds are a homologous series of compounds containing a .............................. type ring structure. .............................................. (C 6H6) is the simplest aromatic compound. 12. Benzene does not decolourise ..................................... solution. This shows that there are no carbon to carbon ................................ bonds in the molecule. Benzene does not react by addition. The benzene molecule has the following structure the ring shows the ............................................. electrons which make the structure very stable. 13. A benzene ring in which one hydrogen atom has been replaced by another atom, or group of atoms, is known as a ....................................... group. A ................................. group has the formula C 6H5. Section (d) – Reactions of organic compounds. (i) Addition reactions 1. Alkenes react quickly by .......................................... across the carbon to carbon ................................. bond. 2. Alkenes can undergo addition of ................................................. (hydrogenation) to form alkanes. 3. Alkenes can undergo addition of .............................................. (halogenation) to form dihalogenalkanes. eg H H C H H C + C H Br H Br H H H C C C C Br Br H H C H H H H H .................................................. + bromine --> ............................................................... 4. Alkenes can undergo addition of hydrogen halides to form halogenoalkanes. H eg H H H C H C H H C + H Br H ..................................... + H C C H H Br ..................................... H H C H hydrogen bromide H H H C C C H H H Br ..................................... 5. Alkenes undergo addition of steam (hydration) to form alcohols. H H H C C H H C C H H H C H + H O C H H O H H ..................................... H ..................................... H + water 10 H H H H C C C H H H O H ..................................... 6. Alkynes also react by addition across the ............................. covalent bond. e.g H H H C C H + H H C Br ......................... + hydrogen bromide H C C H C H H + H Br Br Br ..................................... Br bromoethene + hydrogen bromide Br H H C C H H Br ..................................... (ii) Dehydration of alcohols Alcohols can be dehydrated (loss of .............................) by passing the alcohol vapour over heated aluminium oxide (catalyst) to form alkenes. eg. H H H H H C C C H H H O H --H2O H -H2O H C C H C H H propan-1-ol .................................. (iii) Oxidation reactions 1. Alcohols burn in oxygen, or air, forming ..................................... ................................... and water. eg. Br .................. + ............................ C2H5OH + 3O2 2. Alcohols can be classified as primary, ........................................... or ................................................. eg H H H H Br O O H H C C C H H H H H C H H C H C C H H H H H H H C C C H H H O H H propan-2-ol is a ........................... alcohol 2-methylpropan-2-ol is a ............................... alcohol propan-1-ol is a ............................ alc ohol 3. Primary and secondary alcohols can be oxidised using oxidising agents such as a) acidified potassium dichromate solution. In this reaction the orange .............................. ion is reduced to the ............................ chromium(III) ion. b) hot copper(II) oxide. In this reaction the black copper(II) oxide is reduced to ....................... copper metal. 11 4. Oxidation of a primary alcohol first produces an ............................................... which then is oxidised further to a ............................................... acid. eg H H H C C H H H O -- 2H H H C - 2H H + O C H O H H C H +O O C O H ethanol .................................. ............................. acid 5. Oxidation of a secondary alcohol produces a ........................................... eg O OH CH3 -- 2H CH CH3 CH3 C - 2H CH3 propan-2-ol ................................... 6. Aldehydes but not ketones can be oxidised to ................................................. acids. Suitable oxidising agents include Fehlings solution. The blue copper(II) ion in the Fehling’s solution is reduced to ............................................ copper(I) ions. eg O O CH3 CH2 CH2 + O CH CH3 CH2 CH2 C +O OH butanal ....................................................... Section (e) - Making and breaking esters. 1. Esters are made in a ................................................... reaction between and alcohol and a ...................................................... acid. eg O H H H C C + H H O O C + H H 2O .................................... H H .................................... acid The ........................... methylethanoate + water shows that the reaction is .................................................... 2. The breaking of an ester into an alcohol and a carboxylic acid is an example of a ................................. O reaction. H C eg H H C C H O H C H H + H2O C H H ........................ H ............................................................... water ethanol 12 ............................. + propanoic acid Section (f) - Percentage yields. Percentage yields can be calculated using the masses of reactant(s) and product(s) from balanced equations (See separate booklet on Higher Chemistry calculations). Section (g) - Uses of organic compounds. 1. Esters are used as solvents, ....................................... bases. and food .............................................. 2. Carboxylic acids are used to make esters and polyesters. A dilute solution of ethanoic acid is used a .....................................( a food preservative). Benzoic acid is used as an anti-................................. food preservative. 3. Halogenoalkanes such as chlorofluorocarbons (CFCs) were widely used as ............................................ in fridges and freezers, .................................... propellants and for degreasing circuit boards. CFC’s are however also known to destroy ..................................... (O 3) in the upper atmosphere. As ozone in the upper atmosphere protects us from ..................................... radiation from the Sun, the depletion of the ozone layer posed an increased threat of skin ............................. and cataracts. Manufacture and use of ................... has now been banned. 4. Benzene and its related compounds are important feedstocks – chemicals from which other chemicals can be synthesised. Section (h) - Polymers. 1. Ethene is a starting material of major importance in the manufacture of addition polymers. Ethene is obtained by the ............................... of ethane found in natural gas. C2H6 ethane ............................. + ethene + H2 hydrogen 2. Ethene can also be obtained by cracking the .......................................... fraction obtained from the distillation of crude oil. 3. Propene can be obtained by the cracking of .................................... or the cracking of naphtha. 4. Poly(ethene) and poly(propene) are .......................................... polymers made by addition polymerisation. Show below how 3 propene monomers can undergo addition polymerisation 5. Condensation polymers are made from monomers with ...................... functional groups per molecule. 13 6. Polyesters are condensation polymers made by a reacting a ................................... (two –OH groups) with a ........................................... ( two –COOH) groups eg Shown below a two molecules of ethane-1,2-diol and benzene-1,4-dicarboxlic acid Complete the diagram to show part of the polyester formed when these 4 molecules react. Once drawn, circle the ester links in the polymer. O H O H H C C H H O C O H O C O O H H O H H C C C O H H H O C O O H H H 7. Polyesters are manufactured for use as textile fibres and as resins. Polyesters used as textile fibres have a ....................................... structure. Polyesters used as resins have a ........................................ - ............................................. 3 dimensional structure. 8. An amine is a molecule which contains the ............................... (-NH2) functional group. 9. Polyamides are condensation polymers made by reacting a diamine (a molecule with two ............... groups) with a diacid ( a molecule with two ............................... groups). Nylon is an example of a polyamide. One version of nylon can be made by reacting 1,6-diaminohexane with hexane-1,6-dioic acid. Complete the diagram to show part of the nylon polymer formed when these 4 molecules react. Once drawn, circle the amide links in the polymer O H O H H H H C C C C N C H H H H O O CH H H C C H H H C N O H H H H C C C C H H H H H O O H H H C N H O H H H H H C C C C C C H H H H H H H C H H H H C C C C H H H H N O H H H O H H 10. Nylon is so strong that it can be used as an engineering plastic. The strength of nylon is due to the many .................................. bonds between polymer chains.. O H C H H H H H H O H H O H C C C C H H H H C O 14 O C O H 11. Methanal (H2C=O) is an important feedstock in the manufacture of ................................................... polymers such as Bakelite and urea-formaldehyde resin. 12. Methanal is formed by the oxidation of ..................................................... 13. Methanol (CH3OH) is made from .......................................... gas ( a mixture of hydrogen and carbon monoxide) CO(g) + 2H2(g) ....................... 14. Synthesis gas, a mixture of ...................................... ................................... and ..................................... can be made by a) steam reforming of coal C(s) + H2O(g) ............. + ............... b) steam reforming of methane CH4(g) + H2O(g) ............ + ................ 15. Kevlar is an aromatic polyamide. Kevlar is very light and ....................................... Kevlar is used to make ...................................................... vests. 16. Poly(ethenol) is a ............................. soluble polymer. It is used to make dissolving hospital laundry bags. 17. Poly(ethyne) can be treated to make a polymer which ......................................... electricity. 18. Biopol is a ........................................................ polymers. 19. Poly(vinylcarbazole) is a photoconductive polymer used in the manufacture of ...................................... Section (i) – Natural products (Fats and Oils). 1. Fats and oils are naturally occurring esters. Fats and oils can be classified according to their origin – animal, ......................... or ...................................... 2. Oils have ........................................... melting points than fats. The ....................................... melting points of oils is due to the oils being ............................................................. molecules. The fact that oils are ..................................................... can be shown by the fact that oils quickly decolourise ............................. solution. 3. Fat molecules are more linear in shape than oil molecules. This means that fat molecules can pack together .................... closely than the more angular oil molecules. Since the fat molecules can pack together more closely than oil molecules the van der Waals forces between fat molecules are ..................................... than between oil molecules. 4. The conversion of unsaturated oils into solid fats in margarine manufacture involves the addition of ......................................... (hydrogenation) across some of the double bonds in the oil molecules. 5. Fats and oils are a ....................... concentrated source of energy in the body than carbohydrates. 6. The hydrolysis of a fat (or oil) produces a mixture of ...................................... (propane-1,2,3-triol) and ............................. acids (long chain carboxylic acids) in the ratio of one molecule of ........................................... to three molecules of fatty acid. 15 7. Glycerol (propane-1,2,3-triol) is a trihydric alcohol. This means it contains three .......................... (-OH) functional groups per molecule. 8. Fats and oils are triglycrerides formed when one molecule of .......................................... combines with ............. fatty acid molecules. The fatty acid molecules may, or may not, be identical. 9. Soaps are produced by the alkaline hydrolysis of ................... and ..................... Section (j) – Natural products (Proteins and amino acids). 1. Proteins are condensation polymers made by combining together many ......................... ........................... monomer molecules. 2. Proteins are required by the body for ........................ and tissue ................................... 3. Proteins and amino acids contain the elements carbon, hydrogen, oxygen and ...................................... 4. The body cannot make all the amino acids required to make body proteins. The supply of these .............................................. amino acids depends on the diet we eat. 5. Amino acids are molecules that contain a basic amino (...............) group and an acidic ............................. (-COOH) group. The simplest amino acid is 2-aminoethanoic acid. The extended structural formula is shown below 6. Shown below is a small part of a protein polymer chain H H C H O H N H N H H C H C C H C O O H N H C C H N H H Circle the peptide (amide) links shown in this part of the protein molecule. Draw the extended structural formula of the two amino acids produced by the hydrolysis of this part of the protein molecule. 16 7. Protein molecules can be classed as fibrous (..................... and thin) or globular (spiral chains folded into ........................). Fibrous proteins are form many of the bodies major structural units such as muscles and tendons. Globular proteins form many of the enzymes and hormones in the body. For example haemoglobin in .................. blood cells and insulin are both ............................. proteins. 8. Enzymes are .................................... molecules. Enzymes are very specific ie they usually only catalyse one particular reaction in the body. This is because the molecule which is to react must exactly match the size and shape of the ................................. site on the surface of the enzyme molecule. 9. Changes in pH or an increase in temperature can .................................. the size and shape of the active site. When this happens the enzyme loses its catalytic effect – we say the enzyme has been ............................................................. 17 Unit 3 Section (a) – The Chemical Industry 1. The chemical industry is a major contributor to the ...................................... of the UK. 2. Stages in the production of a new product involve research, pilot production, scaling up to ............................... scale production and review. 3. A ...................................... is a chemical from which other chemicals can be synthesised or extracted. 4. The major ............. materials used by the chemical industry are fossil ..................., metallic .............. and minerals, air and ............................... 5. Chemicals may be manufactured in a batch or ................................................... process. A batch process is used to make ........................ quantities of speciality chemicals where purity is important eg in the manufacture of drugs and .......................................... The reaction vessels used to make chemicals in a batch process can be used to make many different .................................... The reaction vessel has to be carefully cleaned between the making of one product and another. Continuous processes are more suited to situations where ......................... quantities of a single product are being made eg fractional distillation of ..................... ......................, making cement and making iron in a ............................ furnace. 6. The manufacture of chemicals involves both fixed costs and .................................... costs. Fixed costs are the costs that are incurred no matter how much of the product is made eg the cost of plant and ............................................, land ............................ and labour costs. Variable costs depend on how much product is made eg energy costs associated with production. the cost of ..................... materials and the costs of ......................................... finished product to the consumer. 7. The chemical industry is capital intensive rather than ...................................... intensive. Section (b) – Hess’s Law 1. Hess’s law states that the enthalpy change for a reaction is .................................................... of the reaction pathway. 2. Enthalpy changes can be calculated by an application of Hess’s Law . (See separate booklet on Higher Chemistry calculations). Section (c) – Equilibrium 1. Reversible reactions attain a state of dynamic equilibrium when the ................... of the forward reaction equals the .......................... of the ................................................. reaction. 2. At equilibrium the concentrations of the reactants and products remains .......................................... It is important to realise that at equilibrium the concentrations of reactants and products will not usually be ..................................... 3. Increasing the concentration of one of the reactants will speed up the .................................... reaction and shift the equilibrium from ....................... to right ie it will result in an increased yield of ............................... 18 4. ............................................ the temperature will favour the endothermic step in a reversible reaction. ............................................. the temperature will favour the exothermic step in a reversible reaction. 5. Increasing the pressure will favour the reaction which forms fewer ........................ phase molecules. Decreasing the pressure will favour the reaction which forms more ....................... phase molecules. 6. In the Haber process N2(g) + 3H2(g) 2NH3(g) DH = --92 kJ The yield of ammonia will increase by ........................................ the temperature, .................................. the pressure and recycling unreacted nitrogen and hydrogen (as this has the same effect as increasing the ........................................... of these reactants). 7. Low temperatures favour the formation of .......................................... in the Haber Process. However, if the temperature is too low the ............................. of production of ammonia is too slow. A compromise temperature of about ................. is used to give a reasonable yield at a reasonable rate. 8. A catalyst speeds up the rate at which a reaction reaches ................................................. Using a catalyst does not, however, alter the position of the equilibrium as it speeds up the forward and reverse reactions by the ........................ amount. Section (d) – Acids and Bases 1. The pH scale is a continuous number scale that runs from below .............. to above ................... 2. A solution with a pH of ......... has a hydrogen ion concentration of 1 x 10 -1 mol l-1. A solution with a pH of ......... has a hydrogen ion concentration of 1 x 10 -2 mol l-1. A solution with a pH of ......... has a hydrogen ion concentration of 1 x 10-3 mol l-1 etc. 3. In water and aqueous solutions with a pH of 7 the ......................................... ion concentration, [H +(aq)], = the ................................... ion concentration, [OH -(aq)]. Both have a value of .......................... mol l-1. 4. The concentration of either hydrogen ions or hydroxide ions in an aqueous solution can be calculated from the concentration of the other using the fact that [H+(aq)] x [OH-(aq)] = ................................. mol2 l-2. 5. In water, and aqueous solutions, there is an .............................................. between hydrogen ions, hydroxide ions and water molecules. H2O(l) H+(aq) + OH --(aq) The equilibrium lies far to the ............................... ie most of the water exists as ................................... 6. In aqueous solution strong acids are .................................... ionised. Weak acids are only ........................ ionised. 7. When equimolar (same concentration) solutions of a strong acid and a weak acid are compared the strong acid has a ................................. pH, a ...................................... conductivity and a ................................ reaction with magnesium than the weak acid. However, the same volume of both the strong acid and the weak acid will neutralise the ................... number of moles of a given alkali. 19 8. Carboxylic acids such as ethanoic acid are ........................ acids. CH3COOH(l) + H2O(l) ......................................... + ....................... The equilibrium for the reaction lies far to the ............................ ie it exists mostly as ...................................... with very few ............................. present. 9. Solutions formed when sulphur dioxide and carbon dioxide dissolve in water are ...................... acids. For example:SO2(g) + H2O(l) ....................... + ................................ sulphurous acid As with all weak acids the equilibrium lies far to the ................................ 10. In aqueous solutions strong bases are ................................ ionised. Weak bases are only ........................ ionised. 11. When equimolar (same concentration) solutions of a strong base and a weak base are compared the strong base has a ................................. pH, and a ...................................... conductivity. However, the same volume of both the strong base and the weak base will neutralise the ................... number of moles of a given acid. 12. The solution formed when ammonia gas (NH3) dissolves in water is a ..................... base. NH3(g) + H2O(l) .......................... + .............................. ammonium hydroxide solution 13. A soluble salt formed when a strong acid reacts with a strong base is ............................................ (pH = ..........) eg sodium chloride is the salt formed when ............................................... acid reacts with ......................................... ............................................ Sodium chloride is a ................................ salt 14. A soluble salt formed when a strong acid reacts with a weak base is ............................................ (pH < ..........) eg ammonium sulphate is the salt formed when ................................................. acid reacts with ...................................... ....................................... Ammonium sulphate is a ............................. salt. 15. A soluble salt formed when a weak acid reacts with a strong base is ............................................ (pH > ..........) eg potassium carbonate is formed when ...................................... acid reacts with ..................................... ..................................... Potassium carbonate is a ........................... salt. 16. Soap solutions are ............................................ as soap is the salt of a weak acid and a strong base. 20 17. Ammonium chloride dissolves in water to form an ............................... solution. Ammonium chloride is very ..................................... in water and produces lots of ammonium and chloride ions in solution. NH4Cl(s) + H2O(l) NH4+(aq) + Cl --(aq) In water there is an ........................................ between water molecules, hydrogen and hydroxide ions. H2O(l) H+(aq) + OH--(aq) As ammonium hydroxide is a ......................... base there is a strong tendency for the ammonium and hydroxide ions to react to form ammonia and water molecules. NH4+(aq) + OH--(aq) NH3(g) + H2O(l) There is no such tendency for hydrogen and chloride ions to react as hydrochloric acid is a ................................. acid and remains fully ionised. The removal of the ................................... ions leaves behind a solution with an excess of hydrogen ions – ie an ............................... solution. Section (e) – Oxidation and Reduction reactions 1. Oxidation involves a ........................... of electrons. Reduction involves a ...................... of electrons. 2. An oxidising agent is itself ......................................... An oxidising agent is an electron ............................... A reducing agent is itself ........................................ A reducing agents is an electron .................................... For example in the displacement reaction shown below Zn(s) + 2Ag+(NO3--)2(aq) Zn2+ (NO3--)2(aq) + 2Ag(s) In this reaction the zinc is the .......................................... agent. The ion-electron equation for the oxidation of the zinc atoms is:........... ................... + ................. In this reaction the silver(I) ions are the .......................................... agent. The ion-electron equation for the reduction of the silver(I) ions is:............... + ............. .................. In this reaction the nitrate ions are called the ........................................................... ions. 3. To combine together the oxidation and reduction ion-electron equations into the balanced redox equation we must first balance the number of .................................... lost and gained in the oxidation and reduction reactions. eg oxidation Fe2+(aq) Fe3+(aq) + e -reduction MnO4--(aq) + 8H+(aq) + 5e -Mn2+(aq) + 4H2O(l) To construct the redox equation we must first multiply the oxidation reaction by ........... This gives ........... Fe2+(aq) ........ Fe3+(aq) + ........ e -Adding together the oxidation and reduction reactions gives the balanced redox equation ............................................................................................................................. ......................................................... From this equation it can be seen that ............ moles of Fe2+(aq) ions are oxidised by ............... mole of MnO4-(aq) ions. 21 4. Given the reactant and product species an ion-electron equation reaction involving H+(aq) and H2O(l) can be constructed. eg Construct the ion-electron equation for the conversion of iodate (IO3-) ions to iodine. Step 1:- balance the iodine atoms on each side: ..........IO3--(aq) I2(aq) Step 2:- Add H2O(l) molecules to balance the oxygen atoms on each side ..........IO3--(aq) I2(aq) + ........H2O(l) Step 3 :- Add H+(aq) ions to balance the hydrogens on each side ..........IO3--(aq) + .........H+(aq) I2(aq) + ........H2O(l) Step 4:- Add electrons to balance the charge on each side ..........IO3--(aq) + .........H+(aq) + ....... e -- I2(aq) + ........H2O(l) In this reaction the iodate is ................................. to iodine. The iodate is acting as an ............................................ agent. 5. You must be able to carry out calculations based on redox titrations. . (See separate booklet on Higher Chemistry calculations). Section (f) – Faradays Laws of Electrolysis 1. The production of one mole of an element always requires n x .............................. C where n is the number of electrons in the relevant ion-electron equation. For example:- the electrolysis of copper(II) chloride produces copper at the .................................. electrode and chlorine at the ................................. electrode. The ion-electron equation for the production of copper is:Cu2+(aq) + 2e -Cu(s) The production of one mole of copper requires ........... x 96500C (or ........... Faradays) The ion-electron equation for the production of chlorine is:2Cl --(aq) Cl2(g) + 2e -The production of one mole of chlorine requires ........... x 96500C (or ........... Faradays) 2. You must be able to carry out calculations based on Faradays laws of electrolysis. (See separate booklet on Higher Chemistry calculations). 3. The charge on one mole of electrons is one Faraday (................................ Coulombs) Section (g) – Nuclear Chemistry 1. Radioactive decay involves changes inside the .................................. of atoms. 2. Unstable nuclei (radioisotopes) become more stable by the ........................ of energy and the emission of radiation. 3. The stability of a nucleus depends on the ratio of the ............................ to ................................. inside the nucleus. 22 4. The table below summarises the properties of alpha (), beta () and gamma () radiation. Type of radiation Symbol Charge Mass alpha or 42He 2+ ............. ............. towards the ........................... plate or ............ ............ towards the ...................... plate ............. ............. ................................................... beta gamma e -- 0 -1 Deflection in electric field 5. You must be able to write balanced nuclear equations involving protons, neutrons, alpha and beta particles eg Complete the nuclear equations for the following reactions:1) Uranium-238 decaying by alpha emission U 238 92 .................... + ............... 2) Radium-228 decaying by beta emission Ra 228 88 .............. + .................. 3) Nitrogen-14 capturing a neutron and the then breaking down into carbon-14 and a proton N + 14 7 n 1 0 ...................... + ................. 6. The .................... -........................ is the time taken for the activity, or mass, of a radioisotope to fall to half its original value. 7. ................ - ........................ of radioisotopes of independent of the chemical or physical state of the radioisotope. For example, the half life of lead-214 is ......................... minutes (see data book page 8). It could be 214 present as 10g of 214 Pb or as 0.5 g of 82Pb or as 5kg of 214 PbO the half life would be the .................. 82 82 in all three. 8. The mass of a radioisotope, half-life or time elapsed can be calculated given the value of the other two variables. For example:A 10g sample of Thorium-234 has a count rate of 440 counts per minute. Using the half life given in the data booklet, calculate i) the mass of Thorium-234 remaining after 96.4 days ii) the count rate after 72.3 days. 23 9. Radioisotopes are used in a) Medicine. Cobalt-60 emits gamma rays which can be used to kill deep seated ................................. tumours. Radioisotopes of iodine such as Iodine-131 can be used to detect anomalies in the ........................ gland. b) In industry. Gamma rays from a cobalt-60 source can be used to check for hairline ............................ in metals. A beta emitter can be used to continuously monitor the ........................................... of paper in a paper mill. c) Scientific research Radioactive carbon-14 can be used to date .......................................... remains. By comparing the ratio of carbon-14 to carbon-.......... in the organic remains to a sample from the present day the age of the remains can be estimated. Radioactive isotopes of phosphorus can be used to determine the use of .......................................... fertilisers by different plants. d) Energy production by nuclear fission Uranium-238 is a radioisotope of uranium that can undergo nuclear ................................... (splitting of a ....................... nucleus into two, or more, lighter nuclei). In the process energy is ....................... .................... The reaction is a chain reaction in which the fission is started when a uranium-238 atoms absorbs a ............................ forming an unstable uranium-239 atom which then breaks down (fissions) forming two or more stable atoms and releasing more ............................... which can go on to react with more uranium-238 atoms. e) Energy production in the Sun by nuclear fusion. Inside the Sun light atoms are ............................. together to form heavier atoms and in the process ......................... is given out. 4 eg 2H + 3H He + ............ 1 1 2 10. There are advantages and disadvantages of using fossil fuels and nuclear energy to electricity . The advantages of fossil fuels is that they are relatively .................... and readily ................................. The disadvantages of fossil fuels is that they give out harmful gases such as ....................................... .................................................... which is the main Greenhouse gas linked to Global warming. The advantages of nuclear fuels is that they do not give out harmful ............................... which cause damage to the environment. The disadvantage of nuclear power stations is that they produce harmful ........................................... waste which will remain highly .......................................... for .......................................... of years. 11. Elements are created inside ............................ by the process of nuclear ................................ 24 Questions from past SQA Papers (Section B) for you to test your knowledge. Unit 1 Section (a) – Reaction Rates (including calculations on excess) 2004 Question 6 2003 Question 7 (a) 2003 Question 11 (c) 2002 Question 8 (a) 2001 Question 3 2000 Question 2 Section (b) – Enthalpy 2004 Question 8 (a) 2001 Question 13(b) 2003 Question 11 (a) and (b) 2000 Question 5 Section (c) – Patterns in the Periodic Table. 2004 Question 9 2002 Question 1 2000 Question 7(a) 2000 Question 13 (a) 2003 Question 9 2002 Question 9 2002 Question 6 2000 Question 6 2001 Question 12 Section (d) - Bonding, structure and properties of the first 20 elements 2004 Question 1 Section (e) – Bonding and structure of compounds and Section (f) – Properties associated with bonding 2002 Question 7 2003 Question 12 2001 Question 11(b) Section (g) – The Mole 2004 Question 2 (b) (i) 2003 Question 10 (c) 2001 Question 4 2000 Question 13 (b) 2004 Question 11 2003 Question 11 (d) 2000 Question 7(b) (c) 2003 Question 3 (c) 2002 Question 12 (b) 2000 Question 10 Unit 2 Section (a) – Fuels 2004 Question 10 (b) 2001 Question 1 2003 Question 1 (b) 2001 Question 11 (a) (iii) Section (b) – Alternative fuels 2004 Question 4 (c) Section (c) – Nomenclature and structural formulae. 2004 Question 10 (a) (iii) 2003 Question 1(a) 2001 Question 11 (a) (i) 2000 Question (b) Section (d) – Reactions of organic compounds. 2004 Question 4 (a) and (b) 2004 Question 10 (a) (i) and (ii) 2003 Question 8 2002 Question 5 (a) (ii) to (iv) 2001 Question 2(a) 2001 Question 10 (a) Section (e) - Making and breaking esters. 2004 Question 14 2003 Question 6 (a) and (b) 2000 Question 9 (a) 25 2001 Question 8 (a)(i) 2004 Question 13 2002 Question 13 2000 Question 11 2002 Question 5 (a)(i) (b) Section (f) - Percentage yields. 2003 Question 6 (c) 2002 Question 10 (d) 2000 Question 14 (a) (iii) Section (g) - Uses of organic compounds. Section (h) - Polymers. 2003 Question 2 2001 Question 5 2003 Question 5 2001 Question 9 2002 Question 11 2000 Question 14(b) Section (i) – Natural products (Fats and Oils). 2002 Question 3 2001 Question 17 Section (j) – Natural products (Proteins and amino acids). 2004 Question 7 2001 Question 8 (b) 2000 Question 3 Unit 3 Section (a) – The Chemical Industry 2003 Question 14 2000 Question 17 Section (b) – Hess’s Law 2004 Question 15 (a) 2001 Question 7 2003 Question 4 2001 Question 10(b) 2002 Question 4 (b) 2000 Question 12 (c) Section (c) – Equilibrium 2004 Question 5 2001 Question 2(b) 2003 Question 10 (a) and (b) 2000 Question 8 2002 Question 10 (a) to (c) Section (d) – Acids and Bases 2004 Question 8 (b) 2003 Question 13 2001 Question 13(a) 2004 Question 15 (b) 2002 Question 8 (b) 2000 Question 9 (b) 2003 Question 7 (c) 2001 Question 8(a)(iii) Section (e) – Oxidation and Reduction reactions 2004 Question 12 2004 Question 16 2002 Question 15 2001 Question 14 2000 Question 15 Section (f) – Faradays Laws of Electrolysis 2004 Question 3 2002 Question 14 (a) Section (g) – Nuclear Chemistry 2004 Question 2 (a) and 2 b(ii) 2001 Question 1 2003 Question 3 (a) and (b) 2000 Question 4 Miscellaneous problem solving type questions 2004 Question 17 2003 Question 7 (b) 2002 Question 4 (a) 2001 Question 6 (a) to (c) 2000 Question 14 (a) 2000 Question 16 26 2002 Question 14 (b) 2001 Question 15 2001 Question 6(d) 2002 Question 2 2003 Question 15 2001 Question 16) Questions from past SQA Papers (Section A M/C) for you to test your knowledge. Unit 1 Section (a) – Reaction Rates (including calculations on excess) 2004 Q 6 2003 Q 6 2002 Q 4 2001 Q 5 2000 Q 5,6,33 2002 Q 5, 6 2001 Q 6,7 2000 Q 7 Section (b) – Enthalpy 2004 Q 8 2003 Q 7 Section (c) – Patterns in the Periodic Table. 2004 Q 9, 11 2003 Q 9 2001 Q 8 2000 Q 8,9 Section (d) - Bonding, structure and properties of the first 20 elements 2004 Q 10 2003 Q 10 2001 Q 9 Section (e) – Bonding and structure of compounds and Section (f) – Properties associated with bonding 2004 Q 12 2003 Q 8, 11, 12, 13 2002 Q 7, 8 2001 Q 10,11, 31 2000 Q 10 2001 Q 4, 12,13,14 2000 Q 11,32 Section (g) – The Mole 2004 Q 7, 13,14,15 2003 Q 5, 14, 15, 16 2002 Q 10, 11, 12 Unit 2 Section (a) – Fuels 2004 Q 16 2002 Q 13,14 2001 Q 16 Section (b) – Alternative fuels 2001 Q 15 Section (c) – Nomenclature and structural formulae. 2004 Q17, 18 2003 Q 18, 19 2002 Q15 2001 Q 17 Section (d) – Reactions of organic compounds. 2004 Q21 2003 Q 20, 21, 22, 2002 Q 17,18 2001 Q 18, 19, 21, 33 2000 Q 13 Section (e) - Making and breaking esters. 2002 Q 16 2001 Q 20 2000 Q 12 Section (f) - Percentage yields. Section (g) - Uses of organic compounds. 2003 Q 23 2001 Q 22 2000 Q 14 Section (h) - Polymers. 2004 Q19, 23, 24,25 2003 Q 24 2002 Q 19,20,21 2001 Q 23 2000 Q 15, 16,17 Section (i) – Natural products (Fats and Oils). 2004 q 26, 27, 2003 Q26, 27 2000 Q 1934 Section (j) – Natural products (Proteins and amino acids). 2004 Q 28 2003 Q 25, 28 2002 Q 22 27 2001 Q 24, 32(a) 2000 Q 18 Unit 3 Section (a) – The Chemical Industry 2004 Q 29, 2003 Q 29 2001 Q 25, 26 2000 Q 20 Section (b) – Hess’s Law 2004 Q 30, 2003 Q 30 2002 Q 23 2000 Q 21 2002 Q 24 2001 Q 27, 34 2002 Q25,26 2001 Q 28, 29,35 Section (c) – Equilibrium 2004 Q 22, 31, 32, 2003 Q 31, 32 2000 Q 22,23 Section (d) – Acids and Bases 2004 Q 33, 34, 36, 2003 Q 33, 34,35 2000 Q 24,25,26, 31 Section (e) – Oxidation and Reduction reactions 2004 Q 37, 38, 2003 Q 36, 37 2002 Q 27 2000 Q 27 Section (f) – Faradays Laws of Electrolysis 2002 Q 28 2000 Q 28 Section (g) – Nuclear Chemistry 2004 Q 39, 40 2003 Q 38, 39, 40 2002 Q 29,30 2001 Q 30, 32(b) 2000 Q 29,30 Questions from S Chemistry course 2004 Q 1,2,3,4 2003 Q 1,2,3,4 2002 Q 1,2,3 Miscellaneous questions 2004 Q 5, 20, 35 2002 Q 9 28 2001 Q 1,2,3 2000 Q 1,2,3,4