The following is a summary of the key concepts that should be known prior to attempting the Unit 4 VCE Chemistry examination. Chapter references are to Chemistry Dimensions 2.

Chapter 9   An introduction to Industrial Chemistry

• Producing chemicals on a large scale
• Particle motion (Boltzman distributions at varying temperatures)
• Energy changes in chemical reactions (heat change diagrams, exothermic and endothermic, activation energy)
• The rate of chemical reactions (factors that affect rate: temp, conc, surface area, catalysts, explain in terms of particle motion and energy)
• Catalysts (effect on activation energy, homo and heterogeneous catalysts)

Chapter 10     Chemical equilibrium

• Reactions are reversible
• The equilibrium law (K: how to calculate it given initial and/or equilibrium concentrations using the table rule I showed you, concentration fraction, manipulating equations to obtain another one and so calculate K for the new one
• The position of equilibrium: Le Chatelier’s Principle. This is critical! What is the effect of temperature, concentration, volume, inert gas on the position of equilibrium and the constant? Learn the rules!! Go over your Equilibrium SAC – this is a very useful one.

Chapter 11      Acid-base equilibria

• Self-ionisation of water and the pH scale (make sure you can interpret the graph of pH of water at various temperatures, practise pH questions for both acid and alkaline solutions, including diprotic acids and bases)
• Acid ionisation constants (calculating the pH of a solution of weak acid of known concentration given K_a, calculate K_a given the pH of a known concentration weak acid, percentage ionisation of a weak acid, pK_a)
• Acid-base indicators (make sure that you check the Data Table for the range of pH over which indicators change and their relevant colour changes
• Buffers (unlikely to come up, but I will discuss in class just in case)
• Competing equilibria (particularly in blood with the bicarbonate ion and carbon monoxide poisoning role on oxyhaemoglobin)

Chapter 12   Industrial chemistry case study

• Sulphuric acid (raw materials, rate and equilibrium considerations of the Contact Process equation, uses of sulphuric acid, waster materials, use of waste energy)

Chapter 13   Energy sources

• Energy changes in chemical reactions (endo and exothermic heat change diagrams, role of catalyst and activation energy/catalysts on these diagrams)
• Non-renewable energy sources (focus on fossil fuels, renewables, the idea of energy conversions and the loss of efficiency, generating electricity using turbines from coal, natural gas, nuclear or wind/hydro)
• Renewable energy sources

Chapter 14        Enthalpy of chemical reactions

• Energy changes in chemical reactions (Hess Law: manipulating given equations to obtain another equation and determining ΔH for the new one, calculating energy given ΔH, calculating ΔH given energy, calculations involving specific heat capacity)
• Thermochemical equations (recognise the difference between the heat of combustion of a fuel (heat from one mole) and a thermochemical equation for that fuel for which the actual equation matters)
• Latent heat and specific heat capacity (E = c x m x ΔT)
• The calorimeter (Important: solution and bomb calorimeters, calibration factor/constant, sources of error with calorimeters)

Chapter 15        Galvanic cells

• Galvanic cells (oxidation/reduction, oxidant/reductant, role of electrodes and salt bridge, standard conditions, these cells as exothermic, spontaneous energy producing reactions, RC+ rule)
• The electrochemical series (make sure you can use the Electrochemical series to predict whether or not a reaction will occur)
• Commercial cells (primary/secondary/fuel cells and what these terms mean, general structural features of these types of galvanic cell, discharge and recharge equations, pH changes in the sulphuric acid electrolyte of the lead acid accumulator, acidic or alkaline electrolyte equations in fuel cells, electrodes as catalysts in fuel cells)

Chapter 16     Electrolysis

• The electrolytic cell (recognise these cells are effectively the ‘opposite’ of galvanic cells, RC-, endothermic, nonspontaneous energy-requiring reactions, molten or aqueous electrolytes, note that water can undergo oxidation/reduction)
• Industrial applications of electrolysis (focus on the Diaphragm cell for the electrolysis of concentrated salty water, look at Down’s cell (electrolysis of molten NaCl) and Hall-Heroult cell (electrolysis of molten alumina in cryolite)
• Electrolysis calculations (Faraday’s Laws, colulombs, Faradays of charge, current, voltage, E =VQ, using Faraday’s Laws to calculate mass, time, charge on cation species and (advanced) Avogadro’s Constant