CHALLENGE CHEMISTRY -Higher -

1. CHALLENGE CHEMISTRY-Higher - Section 1 ELEMENTS & BONDING

2. LEARNING OBJECTIVES

3. 1.1. Metallic ElementsOn completing this lesson topic you should be able to: • use a simple diagram to describe bonding in a metal. • explain the term delocalised electron. • explain how the atoms are held together in a metallic lattice. • explain the terms: physical property, malleable, and ductile. • explain how metals are able to conduct electricity. • explain in terms of metallic bonding the malleability and ductility of metals. • relate boiling point trends for metallic elements to the nature of the metallic bond. • relate the strength of the metallic bond to the number of outermost electrons and their distance from the nucleus.

4. 1.2 Monatomic ElementsOn completing this lesson topic you should be able to: • explain why the noble gases are described as monatomic • name the only type of bonding that can occur between atoms of the noble gases and describe its relative strength. • explain how this type of attraction can occur between all atoms. • explain what a temporary dipole is and what the signs s+ and s- mean. • explain how Van der Waals forces are affected by the sizes of the atoms involved. • explain the trend in boiling points of the noble gas family in terms of the bonding forces present.

5. 1.3 Molecular ElementsOn completing this lesson topic you should be able to: • name and write formulae for examples of molecular elements. • explain how atoms are held together by a covalent bond. • describe the two types of bonding present in a molecular element. • explain why molecular elements have only low or moderate melting and boiling points. • explain the effect of the size of the atoms within a molecule on the melting and boiling points. • explain the effect of the number of atoms within a molecule on the melting and boiling points. • describe the structure and the expected physical properties of a typical fullerene.

6. Number of atoms and Van der Waals

7. Fullerenes

8. 1.4 Covalent Network elementsOn completing this lesson topic you should be able to: • explain what is meant by a covalent network structure. • name three elements with covalent structures. • describe the bonding and structure in diamond and graphite. • relate melting points, boiling points, and hardness of covalent network elements to bonding and structure. • relate the differences in conduction and hardness of diamond and graphite to differences in their bonding and structure. • relate the bonding and structure in diamond and graphite to examples of their uses.

9. 1.6 Ionisation EnergiesOn completing this lesson topic you should be able to: • define the term first ionisation energy and state the units in which it is measured. • illustrate first ionisation using target pictures and symbol equations. • describe and explain the general trend in first ionisation energy on going across a period in the periodic table. • describe and explain the general trend in first ionisation energy on going down a group in the periodic table. • define the term second ionisation energy. • illustrate second ionisation using target pictures and symbol equations. • use a date booklet to obtain information on ionisation energies for the elements.

10. 1.7 Periodic PatternOn completing this lesson topic you should be able to: • explain what is meant by the elements showing a periodic pattern. • explain how Mendeleev arranged the elements in his periodic table. • describe three bold ways in which Mendeleev used his version of the periodic table. • say which type of bonding structure exists in each of the first 20 elements.

11. CHALLENGE CHEMISTRY- Higher - Section 2 COMPOUNDS & BONDING

12. LEARNING OBJECTIVES

13. 2.1 Covalent Network CompoundsOn completing this topic you should be able to: • explain what is meant by a covalent network compound. • describe the bonding and structure in compounds such as silicon carbide and silicon dioxide. • describe and explain the melting points and hardness of such compounds. • describe and explain some uses of covalent network compounds which depend on their bonding structure. • explain how the formula for a covalent network compound is related to its structure.

14. 2.2 Ionic CompoundsOn completing this topic you should be able to: • explain in terms of electron arrangement the type and size of charge on an ion formed from a single atom. • explain why a two-element ionic compound must contain a metallic element and a non-metallic element. • describe the ionic bond in terms of forces of attraction. • describe the bonding and structure of a typical ionic compound such as sodium chloride and explain the use of the terms network and lattice. • explain how the formula of an ionic compound is related to its structure. • describe how the size of an ion affects the strength of the ionic bond.

15. 2.2. Cont’d • name some common molecular ions and explain their charges in terms of electron arrangements. • describe the different types of bonding present in a compound containing molecular ions and explain why their solutions can conduct electricity.

16. 2.3 Covalent Molecular CompoundsOn completing this topic you should be able to: • explain what is meant by a covalent molecular compound • describe the two types of bonding present in a covalent molecular compound. • draw and use outer-electron pictures for covalent molecules to show how stable electron arrangements are achieved in molecular compounds. • explain in terms of bonding forces, the melting points, boiling points and hardness of typical covalent molecular compounds. • describe and explain how the sizes of atoms in molecules affect the melting points and boiling points of molecule compounds. • describe and explain how the number of atoms in each molecule affect the melting points and boiling points of molecular compounds.

17. 2.4 Polar Covalent BondsOn completing this topic you should be able to: • explain why electrons in covalent bonds are not always shared equally. • explain the terms pure covalent bond, polar covalent bond and permanent dipole. • draw a simple diagram to illustrate the charges resulting from a polar covalent bond and explain how these charges arise. • state what electronegativity is and describe how electronegativity values vary across a period and down a group in the periodic table. • describe how electronegativity values can be used to determine the relative polarity of a covalent bond.

18. 2.4 cont’d • draw a diagram of a water molecule to illustrate its shape and the direction of polarity in the bonds. • say what a polar molecule is. • describe how to test a liquid to see if it contains polar molecules.

19. Polar-Polar AttractionsOn completing this topic you should be able to: • draw molecular diagrams showing the directions of polarity in any polar covalent bonds for molecules containing three or more atoms. • decide whether a molecule with polar covalent bonds will as a whole be polar or non-polar. • explain what polar-polar attractions between molecules are and how they compare in strength with van der Waals forces. • describe and explain the solubilities of polar and non-polar molecular compounds in polar and non-polar solvents (providing no other stronger intermolecular forces are present). • explain the differences in boiling point and melting point of polar and non-polar substances of similar molecular size. • explain why the effect of polarity on properties can only be compared for molecules of similar size.

20. 2.6 Hydrogen BondingOn completing this topic you should be able to: • describe the conditions necessary for hydrogen bonding to take place. • compare the strength of hydrogen bonding with other types of bonding. • draw molecular diagrams to illustrate hydrogen bonding. • describe and explain the effect that hydrogen bonding has on the boiling point and melting point of a substance. • describe an experiment to compare the viscosities of molecular liquids. • describe and explain the effect that hydrogen bonding has on the viscosity of a substance.

21. 2.7. WaterOn completing this topic you should be able to: • describe and explain the unusual boiling point of water in relation to the hydrides of the other group 6 elements. • describe and explain the arrangement of water molecules in the structure of ice. • explain in terms of its structure why ice is less dense than liquid water. • explain in terms of structure and bonding why ice is quite a strong substance for a substance composed of such small molecules. • describe and explain what is unusual about ice floating in water. • state and explain which type of molecular compound is likely to be soluble in water. • describe how water molecules are able to allow some ionic compounds to be soluble in water.

22. CHALLENGE CHEMISTRY- Higher - Section 3 REACTION RATES

23. LEARNING OBJECTIVES

24. 3.1 Collision TheoryOn completing this lesson topic you should be able to: • give the two key points in the collision theory of chemical reactions. • explain in terms of collisions why increasing the concentration of a reactant increases the rate of chemical reaction. • describe the effect that decreasing the particle size of a solid reactant has on its surface area. • explain in terms of collisions why decreasing the particle size of a solid reactant increases the rate of chemical reaction. • describe the two effects that increasing the temperature has on the reactant particles. • explain in terms of collisions why increasing the temperature of the reactants increases the rate of chemical reaction.

25. 3.2 CATALYSTS AT WORKOn completing this lesson topic you should be able to: • explain why catalytic converters are fitted to modern cars and describe the reactions that take place in them. • explain what adsorption involves and describes what happens on the surface of a solid catalyst. • explain what ‘poisoning’ is and how it can reduce the surface activity of a catalyst. • explain why lead-free petrol has to be used in cars that are fitted with catalytic converters. • explain the term ‘heterogeneous catalysis’ and give some examples. • describe what is meant by regenerating a catalyst and give an example of this in industry. • explain the term ‘homogeneous catalysis’ and describe an example • explain what enzymes are and give some examples of enzymes in action.

26. 3.3 CONCENTRATION AND RATEOn completing this topic you should be able to: • describe how the reaction between iodide ions and hydrogen peroxide can be used to investigate the effect of concentration on the rate of reaction. • explain why starch is added to the reaction mixture in this experiment. • describe how the stop-point for timing the reaction is determined. • identify variables that require to be controlled in this investigation in order to obtain meaningful results. • state and use the expression for calculating the relative rate of reaction and give the unit used for relative rate. • describe and interpret the shape of graph produced by the effect of changing the concentration of a reactant on the rate of reaction.

27. 3.4 TEMPERATURE AND RATEOn completing this lesson topic you should be able to: • outline how the reaction between potassium permanganate and oxalic acid can be used to investigate the effect of temperature on rate. • describe how the stop-point for timing the reaction is determined. • identify variables that require to be controlled in this investigation in order to obtain meaningful results. • state and use the expression for calculating the relative rate of reaction when investigating the effect of temperature. • describe and interpret the shape of graph produced by the effect of temperature on the rate of reaction. • estimate the temperature rise required to roughly double the rate of reaction.

28. 3.5 REACTION PROGRESSOn completing this topic you should be able to: • describe how the concentration of a reactant or product is affected as a reaction proceeds. • outline some ways in which the progress of a reaction can be followed. • plot and interpret a graph showing the progress of a reaction against time. • explain how the rate of a reaction can be represented and give examples of possible units. • work out the average rate of reaction in a given time interval from a graph of reaction progress or from a given change in quantity of a substance. • plot and interpret a graph showing the rate of reaction against time. • compare and interpret progress graphs for reactions taking place under different conditions.

29. 3.6 ACTIVATION ENERGYOn completing this topic you should be able to: • draw and explain a potential energy diagram showing the energy pathway for a simple reaction. • point out the activation energy and the potential energies of the reactants, products, and activated complex on a potential energy diagram for a reaction. • explain the term ‘activated complex’ and draw a diagram of an activated complex in the reaction between two simple molecules. • explain the term ‘activation energy’, write its symbol, and give the units used when stating activation energies. • calculate an activation energy from a potential energy diagram. • state the effects of a catalyst on: (i) the potential energies of the reactants and products, and (ii) the activation energy of a reaction. • draw a potential energy diagram to illustrate how a catalysts affects the energy pathway for a reaction.

30. 3.7 ENERGY DISTRIBUTIONOn completing this topic you should be able to • draw and explain the shape of an energy distribution graph for molecules. • define activation energy in terms of the kinetic energy of collisions and relate this to energy distribution graphs. • state why light can increase the rate of some reactions. • describe temperature in terms of the kinetic energy of the particles in a substance. • draw and interpret distribution graphs illustrating the effects of (i) changing the concentration of a reactant, (ii) changing the temperature, (iii) introducing a catalyst.

31. CHALLENGE CHEMISTRY- Higher - Section 4 MOLE & ENERGY

32. 4.1 MOLE AND NUMBEROn completing this lesson topic you should be able to: • state the Avogadro constant by giving its symbol, value and units. • state the mole link between the amount of substance in moles and the number of formula units it contains. • carry out calculations using the mole link between the amount of substance in moles and the number of formula units it contains. • state the mole link between the mass of a substance and the number of formula units it contains. • carry out calculations using the mole link between the mass of a substance and the number of formula units it contains.

33. 4.2 MOLE AND GAS VOLUMEOn completing this lesson topic you should be able to: • define the term ‘molar volume’ for a gas and state the unit in which it is measured. • describe an experiment to determine the molar volume of a gas and carry out the appropriate calculation from the results. • state the conditions under which the molar volumes for gases are equal. • use the link between mole volume and mole to carry out calculations involving gas volume and moles. • use the link between mole volume and mole mass to carry out calculations involving gas volume and mass. • use the link between mole volume and mole number to carry out calculations involving gas volume and number of molecules.

34. 4.3 CALCULATIONS INVOLVING COMPARISONSOn completing this lesson topic you should be able to: • compare quantities of substances in terms of moles and formula units. • describe the relationship between equimolar amounts of substances and the numbers of formula units. • work out which reactant is in excess in a reaction and by how much it is in excess. • explain what is meant by the ‘limiting reactant’ in a chemical reaction. • calculate the quantity of a product in a reaction where the limiting reactant has first to be identified

35. 4.4 GASES IN REACTIONSOn completing this lesson you should be able to: • interpret a balanced equation in terms of volumes of gases involved in the reaction. • use a balanced equation to calculate the volume of a product gas from a given volume of a reactant gas, and vive versa. • work out which reactant gas is in excess in a reaction, and by what volume it is in excess. • work out the final total gas volume at the end of a reaction when a specified volume of a gas reacts with a given volume of another gas.

36. 4.5 CHEMICAL ENERGYOn completing this lesson topic you should be able to: • define the terms exothermic and endothermic in terms of energy changes and describe how such changes can be detected. • explain the term ‘enthalpy’ and give its symbol. • draw and interpret enthalpy diagrams illustrating exothermic and endothermic reactions. • explain what happens to the energy difference in such diagrams • explain what ΔH is and calculate ΔH values from enthalpy diagrams. • relate the sign of ΔH to exothermic and endothermic reactions.

37. 4.6 REACTIONS AND ENTHALPY CHANGEOn completing this lesson topic you should be able to: • define the following enthalpy changes: (i) enthalpy of neutralisation (ii) enthalpy of solution (iii) enthalpy of combustion • write appropriate balanced equations for each of these enthalpy changes. • use a data booklet to find appropriate values for such enthalpy changes. • state and use the expression for calculating an enthalpy change from the change in temperature caused in a given mass of water. • calculate a molar enthalpy change from a particular enthalpy change for a given quantity of a substance.

38. 4.7 COMBUSTION OF ETHANOLOn completing this lesson topic you should be able to: • write the balanced equation for the enthalpy of combustion ethanol. • describe an experiment to determine the enthalpy of combustion for ethanol, including a diagram and any special precautions. • carry out the calculation for the enthalpy of combustion from the results of this experiment. • explain why the experimental result differs significantly from the theoretical value.

39. CHALLENGE CHEMISTRY- Higher - Section 5 HYDROCARBONS & FUELS

40. LEARNING OBJECTIVES

41. 5.1 AKANES AND ALKENESOn completing this lesson topic you should be able to: • explain and apply the terms ‘straight chain’ and ‘branched-chain’ in the context of hydrocarbons. • draw full and structural formulae for straight-chain and branched-chain alkanes and (up to C8). • draw full and structural formulae for straight-chain and branched-chain alkenes and give their systematic names (up to C8). • explain the term ‘isomers’ and apply it in the context of hydrocarbons.

42. 5.2 ALKENE REACTIONSOn completing this lesson topic you should be able to: • identify the functional group in an alkene molecule and explain what a double bond is in terms of electron sharing. • name the characteristic reaction of alkenes and explain why it results in the product molecule being saturated. • explain the term ‘hydrogenation’ and describe the conditions for the hydrogenation of an alkene. • write equations for the hydrogenation of alkenes (using full structural formulae, shortened structural formulaqe, and systematic names). • write equations for alkenes reacting with halogens (using full structural formulae, shortened structural formulae, and systematic names.

43. explain why testing an alkene with bromine solution results in the rapid decolourisation of the bromine. • write equations for alkenes reacting with hydrogen halides (using full or shortened structural formulae, and systematic names).l

44. 5.3 ALKYNE FAMILYOn completing this lesson topic you should be able to: • say what is meant by an alkyne and identify the functional group in an alkyne molecule. • explain what a triple bond is in terms of electron sharing. • describe some of the properties of ethyne, such as: appearance, solubility, burning, and reaction with bromine solution. • write systematic names, full structural formulae, and shortened structural formulae for members of the alkyne family (up to C8). • state and apply the general formulae for the alkyne series. • explain how alkynes can undergo addition reactions in two stages and explain whether the products are saturated or unsaturated. • write equations for the reactions of alkynes with hydrogen, halogens, and hydrogen halides (using structural formulae and systematic names).

45. 5.4 HALOGEN DERIVATIVESOn completing this lesson topic you should be able to: • write the full and shortened structural formulae for halogenoalkanes and halogenoalkenes and write their systematic names. • give examples of some of the many uses of these compounds. • explain what CFCs are and give some examples of the early uses of CFC gases. • describe the properties which made CFC gases such useful compounds and state the major environmental problem which they can cause. • describe how ozone is formed in the upper atmosphere and why it is of great benefit to life on our planet.

46. explain how CFC gases come to affect ozone in terms of: (i) the property that allows them to reach the upper atmosphere. (ii) what happens to CFC gases once they reach the upper atmosphere. (iii) how this then affects the ozone layer.

47. 5.5 AROMATIC HYDROCARBONSOn completing this lesson topic you should be able to: • name and draw the structural formula for the simplest aromatic hydrocarbon. • give an explanation of the modern version of the structural formula for this molecule. • give systematic names and draw structural formulae for some other aromatic hydrocarbons. • explain what the phenyl group is. • describe the typical properties of an aromatic hydrocarbon, such as: appearance, solubility, ph, combustion, and effect on bromine solution. • state whether aromatic hydrocarbons undergo addition reactions easily or not.

48. describe the importance of the simple aromatic hydrocarbons.

49. 5.6 PETROL On completing this lesson topic you should be able to: • say how the fuel-air mixture is ignited in a petrol engine and how this produces products which can damage the environment. • explain the term ‘octane number’ and say how it is affected by the degree of branching, or the cyclic or aromatic nature of a hydrocarbon. • explain why lead compounds were once added to petrol. • say which types of hydrocarbon are used in unleaded petrol to improve the efficiency of burning. • explain the term ‘knocking’ when applied to a petrol engine. • explain what is meant by reforming and say which fraction from crude oil is reformed to make petrol.

50. outline the processes for manufacturing petrol from crude oil. • explain why a different blend of petrol is produced in winter.