§-Chemistry Q&A
VIC · VCAA← Chemistry
Chemistry Q&A by dot point
A short Q&A bank for every VIC Chemistry syllabus dot point. Each question and answer is drawn directly from our worked dot-point page, so you can scan key concepts before opening the long-form answer.
Unit 1: How can the diversity of materials be explained?
the structures and properties of allotropes of carbon (diamond, graphite, graphene, fullerenes and carbon nanotubes) and other covalent network lattices including silicon dioxide, explaining their physical properties (including hardness, electrical conductivity, melting point and solubility) in terms of bonding
the principles of mass spectrometry as an analytical technique for identifying elements and compounds, including ionisation, acceleration, deflection and detection, the interpretation of a mass spectrum (m/z, base peak, molecular ion peak, isotope peaks) and an introduction to fragmentation
the nuclear model of the atom (protons, neutrons, electrons), the use of nuclear notation, isotopes, and the calculation of relative atomic mass from isotopic composition determined by mass spectrometry
Apply IUPAC nomenclature to name and write formulae for ionic, covalent and simple organic compounds
the nature of covalent bonding, the construction of Lewis (electron-dot) structures, and the use of valence shell electron pair repulsion (VSEPR) theory to predict the shapes and polarity of simple molecules
electron configurations of atoms up to atomic number 36 using the Schrödinger model (shells, subshells, orbitals; spdf notation), and the explanation of trends in the periodic table including atomic radius, first ionisation energy and electronegativity in terms of core charge, shielding and shell number
Determine empirical and molecular formulae from mass-composition or percentage-composition data, and from combustion analysis
the nature of intermolecular forces (dispersion, dipole-dipole and hydrogen bonding) and the relationship of structure to physical properties of covalent molecular, covalent network and covalent layered (graphite) substances, including the allotropes of carbon
the nature of metallic bonding and the properties of pure metals and alloys, and the nature of ionic bonding and the properties, names and formulas of binary and ternary ionic compounds
Apply the mole concept, including Avogadro's number, molar mass, and basic stoichiometric calculations
Identify and apply IUPAC nomenclature to simple organic compounds (alkanes, alkenes, alkynes, alcohols, carboxylic acids) and recognise their functional groups
the solubility of ionic compounds and covalent molecular substances in water and in non-polar solvents, explained in terms of bond polarity, intermolecular forces and the energy changes (including hydration enthalpy) associated with dissolving, and the formation of saturated and unsaturated solutions
Unit 2: How do chemical reactions shape the natural world?
the reactions of acids with metals, metal oxides, metal hydroxides and metal carbonates (and hydrogen carbonates), including the writing of balanced equations and an explanation of the underlying acid-base or redox process
expressing the concentration of solutions (mol L^-1, g L^-1, %m/v, %m/m, %v/v and ppm) including dilution calculations, and the Brønsted-Lowry model of acids and bases including conjugate acid-base pairs, the distinction between strong and weak (and concentrated and dilute) acids and bases, and the calculation of pH from [H+]
the principles and stoichiometry of gravimetric analysis to determine the concentration or percentage by mass of an analyte in a sample, including precipitation, filtration, washing, drying to constant mass, and the calculation of the analyte from the mass of the precipitate
the principles and use of colorimetry and UV-visible spectroscopy (including the Beer-Lambert relationship) and atomic absorption spectroscopy (AAS), and the use of calibration curves to determine the concentration of an analyte in water
the writing of balanced full, ionic and net ionic equations for reactions in aqueous solution including precipitation, neutralisation and metal displacement reactions, with state symbols
the relative reactivity of metals as shown in the activity series, the prediction of metal displacement reactions in aqueous solution, and the relationship between metal reactivity and reactions with water, acids and oxygen
the polar nature of the water molecule, the intermolecular forces (hydrogen bonding, dipole-dipole and dispersion) that operate between water molecules and between water and solute particles, and the use of these forces to predict relative solubility of substances in water
redox reactions in aqueous solution including the assignment of oxidation numbers, identification of the species oxidised and reduced, and the construction and balancing of half-equations and overall ionic equations in acidic solution
the application of stoichiometric calculations to reactions in aqueous solution, including the use of n = cV and balanced equations to determine limiting reagent, mass or concentration of reactants and products, and percentage yield where appropriate
the distinction between strong and weak acids and bases using the extent of ionisation, the acid ionisation constant Ka and base ionisation constant Kb, and the relationship between the strength of an acid and the strength of its conjugate base
the principles of volumetric analysis including acid-base and redox titrations, the use of primary and secondary standard solutions and indicators, and stoichiometric calculations including back-titration to determine the concentration or amount of analyte
the explanation of the properties of water (including high boiling point, high specific heat capacity, surface tension and the density of ice relative to liquid water) and the role of water as a solvent for polar and ionic substances, including the use of solubility rules to predict precipitation reactions and write ionic equations
the selection and use of appropriate analytical techniques (gravimetric analysis, volumetric analysis, colorimetry, UV-visible spectroscopy and atomic absorption spectroscopy) to determine the concentration of analytes in a water sample, including comparing the suitability of techniques for major and trace analytes
Unit 3: How can design and innovation help to optimise chemical processes?
the use of solution calorimetry and bomb calorimetry to measure the energy released by chemical reactions, including the use of the specific heat capacity of water and q = mcΔT to calculate the energy released by combustion of fuels and the molar enthalpy of combustion
the design and operation of electrolytic cells for the commercial production of chemicals, including comparison with galvanic cells, the polarity of electrodes in each, the difference between molten and aqueous electrolysis, and the application of Faraday's laws using Q = It and n(e) = Q/F to calculate the mass of substance produced or consumed
the concept of dynamic equilibrium for reversible reactions, the equilibrium law expression and equilibrium constant Kc (including the meaning of Q vs Kc and the units of Kc), and the qualitative application of Le Chatelier's principle to predict the effect on equilibrium of changes in concentration, gas pressure (volume), temperature and the addition of a catalyst
the definition of a fuel, the distinction between fossil fuels (coal, crude oil, natural gas) and biofuels (bioethanol, biodiesel, biogas), and the comparison of fuels with reference to energy content per unit mass (in kJ g^-1) and energy density per unit volume (in kJ L^-1) and renewability
the design and operation of galvanic cells, including primary cells, secondary (rechargeable) cells and fuel cells, with reference to the role of anode, cathode, electrolyte, salt bridge and external circuit, and the calculation of cell EMF (E°_cell) from standard electrode potentials at 25°C
the factors that affect the rate of a chemical reaction (concentration, surface area, temperature and the presence of a catalyst) explained using collision theory and the Maxwell-Boltzmann distribution of kinetic energies, including the representation of these effects on energy profile diagrams
redox reactions with reference to the electrochemical series, including the writing of balanced half-equations and overall ionic equations, the identification of oxidants and reductants, the prediction of spontaneous reactions, and the use of standard electrode potentials at 25°C
the writing of thermochemical equations to represent the energy released or absorbed in physical and chemical changes, including the sign convention for ΔH for exothermic and endothermic reactions, and the use of ΔH values with mole ratios to calculate the energy released or absorbed
Unit 4: How are carbon-based compounds designed for purpose?
structures, properties and reactions (condensation and hydrolysis) of the major biomacromolecules in food (carbohydrates, proteins and lipids) and the role of vitamins, enzymes (active site, lock-and-key/induced-fit models, effects of temperature and pH) and the determination of the energy content of food using bomb calorimetry, including the influence of macronutrient composition and glycaemic index
the principles and interpretation of mass spectrometry (molecular ion peak, fragmentation pattern, M+1 isotope peaks) and infrared (IR) spectroscopy (characteristic absorption bands of functional groups) for the identification of organic compounds
Investigate medicinal chemistry (drug action, structure-activity relationships, functional groups, analytical techniques applied to medicines) and sustainable chemistry (the 12 principles of green chemistry, atom economy, renewable feedstocks)
Investigate drug action through receptor and enzyme binding using intermolecular forces, and apply structure-activity relationships (SAR) to explain why functional-group modifications change biological activity
the principles and interpretation of proton (^1H) and carbon-13 (^13C) NMR spectroscopy (chemical shift, integration, n+1 splitting and number of carbon environments) and high performance liquid chromatography (HPLC, retention time and calibration curves) for the identification and quantification of organic compounds
structures, IUPAC nomenclature and properties of the main organic families (alkanes, alkenes, haloalkanes, alcohols, aldehydes, ketones, carboxylic acids, esters, amines and amides) and the recognition of structural isomers (chain, position and functional-group isomers)
characteristic reactions of organic families including substitution (haloalkanes from alkanes and from alcohols), addition (alkenes), oxidation (alcohols to aldehydes/ketones/carboxylic acids), condensation (esterification) and hydrolysis (of esters and amides), and the design of multi-step reaction pathways linking functional-group families
Design, conduct, evaluate and communicate a student-designed practical investigation in chemistry, related to production of energy and/or chemicals, or analysis/synthesis of organic compounds, inspired by a contemporary chemical challenge
Apply the 12 principles of green chemistry to industrial processes, calculate atom economy and percentage yield, and evaluate the sustainability of named chemical processes