Work through electrochemistry, thermochemistry/kinetics/equilibrium, organic and inorganic matter, then quantitative problem solving. Practise each concept in routine, unfamiliar and real-world contexts using the current four-section C5–C8 written examination format.
Chemistry Level 4 course current for 2026 (version 4e amendment approved 16 September 2026); EAS Version 2 (February 2022, listed with current course); Information Sheet Version 2 (February 2026). Frozen sources downloaded 23 September 2026. · guide last reviewed . Always check the current course document on the TASC site ↗.
The written examination is 180 numeric marks across four compulsory 45-mark sections assessing Criteria 5–8, with 3 hours working time and 15 minutes preparation. TASC combines four external criterion ratings with eight internal ratings to determine the final course award; this practice hub's marks are an exam rehearsal scheme, not a percentage weighting for the final award.
Past papers on this subject span more than one course document. Papers written under an older one still work as practice, but the modules they test have changed — the index labels every paper with the course document it was set under.
Each area below lists the concepts named in the course document, what the TASC exam asks of them, and the mistake that most often costs marks.
Oxidation is electron loss and reduction is electron gain. Use oxidation-state changes and balanced equations to identify both agents and show the electron transfer that supports the conclusion.
External Criterion 5: identify and apply electrochemical principles.
Confusing oxidation state with ionic charge, or naming an agent without explaining the electron change.
Build oxidation and reduction half-equations, balance atoms with H2O and H+, balance charge with electrons, then scale and add. Current course version 4e specifies H+(aq); it does not use hydride for acidic balancing.
External Criterion 5: construct half-equations and overall redox equations.
Using H− instead of H+, omitting states/charges, or failing to check total charge.
Use the electrochemical series as reduction potentials, compare compatible redox couples and calculate E°cell under standard conditions. Explain spontaneity through a positive cell potential and the species that accepts/donates electrons.
External Criterion 5: compare electrode potentials and predict redox reactions.
Reversing a half-equation without changing its potential sign, or comparing unrelated oxidiser and reducer species.
A galvanic cell couples oxidation and reduction through an external electron path and internal ion movement. Label anode/cathode, polarity, electrolyte and salt bridge precisely; show electrons travelling through the wire.
External Criterion 5: represent galvanic cells, cell notation and circuit processes.
Calling every spontaneous redox reaction a cell, or drawing electron flow through solution or air.
Electrolysis applies external electrical energy to drive a non-spontaneous change; competing aqueous products depend on species, concentrations and electrode material. Corrosion is an electrochemical process that can be controlled by suitable barriers or sacrificial protection.
External Criterion 5: predict electrolysis products and apply electrochemistry to corrosion and metal processing.
Ignoring competing reactions, or treating corrosion as a non-redox surface change.
Represent energy changes with consistent system boundaries, signs and energy profiles. Explain how bond changes relate to enthalpy and distinguish reaction enthalpy from activation energy.
External Criterion 6: apply thermochemical principles.
Calling a catalyst an energy source or reversing the sign of heat without naming the system.
Use q=mcΔT and supplied calibration terms to estimate heat transfer, then link energy to the amount reacting. Assess heat loss, assumptions, measurement precision and whether a temperature rise means the reaction or surroundings released heat.
External Criterion 6: interpret thermochemistry and evaluate experimental evidence.
Using an unexplained sign convention or reporting a heat value with no units or molar basis.
Rate depends on effective collisions and activation energy. Temperature, concentration, pressure, surface area and catalysts affect collision frequency or the fraction of particles able to react in ways that can be explained from the model.
External Criterion 6: apply kinetics and interpret rate evidence.
Claiming particles move faster because collisions become more frequent, without linking temperature to kinetic energy.
A closed reversible system at equilibrium has equal forward and reverse rates, not necessarily equal concentrations. Write Kc from the balanced equation and omit pure solids and liquids before substituting equilibrium concentrations.
External Criterion 6: calculate and interpret equilibrium constants.
Including solids in Kc or describing equilibrium as a stopped reaction.
Use Q relative to K and Le Chatelier's principle to predict a response to a changed condition, then distinguish rate from final position. Apply Brønsted-Lowry pairs, Ka, Kw, pH and titration evidence to the specific acid-base system.
External Criterion 6: analyse equilibrium and acid-base systems quantitatively and qualitatively.
Saying a catalyst changes equilibrium position, or treating pH as a linear scale.
Electron configuration, effective nuclear attraction, shielding and distance explain periodic changes in properties. Use specific evidence to explain both general trends and the relevant exception.
External Criterion 7: explain properties of inorganic matter using chemical principles.
Stating a trend without a particle-level cause, or confusing oxidation number and charge.
Kinetic molecular theory connects particle motion and collisions to pressure, volume and temperature. Apply the gas equations with kelvin and consistent pressure/volume units, while recognising ideal-gas assumptions and any supplied non-ideal context.
External Criterion 7: explain gas behaviour and inorganic chemical properties.
Using Celsius in a gas equation or claiming ideal particles have no mass rather than negligible volume/intermolecular forces.
Recognise functional groups and represent molecular structure with accepted formula conventions. IUPAC names and complete structural drawings communicate the same chemical identity without ambiguity.
External Criterion 7: identify organic structures and properties.
Naming a broad family when the question asks for a particular molecule, or omitting required hydrogens.
Functional groups determine characteristic reaction pathways; select reagents and conditions that produce the intended product. Explain how yield, purity and polymer structure depend on the route and process choices.
External Criterion 7: demonstrate understanding of organic reactions and chemical synthesis.
Drawing an unbalanced transformation or a polymer repeat unit without bonds continuing through the chain.
Treat IR and mass-spectrometry data as complementary evidence. Identify diagnostic features, test candidate structures against every relevant observation, and relate molecular polarity/intermolecular forces to physical properties where asked.
External Criterion 7: interpret analytical data and explain matter properties.
Giving a structure without citing a diagnostic wavenumber or treating a missing peak as positive evidence.
Use a balanced equation to convert between amount of reactant and product, identify the limiting reagent, and compare actual with theoretical yield. Preserve units and explain what each calculated amount represents.
External Criterion 8: solve stoichiometric chemical problems.
Calculating product from the excess reagent or applying the mole ratio before balancing the equation.
Relate amount, volume and concentration through a balanced reaction ratio. Include dilution, aliquot and titre relationships explicitly so the final concentration corresponds to the original sample.
External Criterion 8: solve solution and titration calculations.
Using burette volume as though it were the total sample volume or skipping the mole ratio.
Use molar mass, composition and gas relationships to infer amounts or formulae. Convert temperature to kelvin, keep pressure and volume units compatible, and check integer atom ratios against the evidence.
External Criterion 8: solve gas, composition and formula problems.
Rounding before the final step or reporting an empirical ratio that is not checked for a whole-number formula.
Select the relationship that matches the supplied quantities, show substitutions and interpret the result chemically. For equilibrium or rate work, check that calculated amounts remain possible and respond to any requested condition change.
External Criterion 8: solve quantitative thermochemistry, kinetics and equilibrium problems.
Using a formula without defining symbols, omitting units, or accepting a negative concentration.
Connect potential, amount of electrons and electrical charge to the specified cell or electrolysis task. Use q=It and Faraday's constant with stoichiometric electron ratios, then report mass, current or time with units and suitable precision.
External Criterion 8: solve quantitative electrochemistry problems.
Using charge without converting through moles of electrons or applying the wrong half-equation coefficient.
Chemistry Level 4 (CHM415115), version 4e, amendment approved 16 September 2026, current for 2026. The exam itself follows External Assessment Specifications Version 2 (February 2022), still listed as current with the 2026 course materials, alongside the Chemistry Information Sheet Version 2 (February 2026) you can use in the exam. One wording detail matters for your working: the current course specifies H+(aq), not H−(aq), when constructing acidic redox half-equations.
No. Chemistry Level 4 (CHM415115) is a separate, higher-complexity course from Physical Sciences Level 3 (PSC315118). TASC recommends completing Physical Sciences first, but Physical Sciences is a prerequisite, not a repeat: its general chemistry content is assumed knowledge going into Chemistry Level 4, not content that reappears on this exam.
The written exam only assesses Criteria 5–8 (electrochemistry; thermochemistry, kinetics and equilibrium; organic and inorganic matter; and quantitative problem solving) — that's what this hub's practice papers and mark model target. Criteria 1–4 (research, practical/laboratory technique, experimental design and scientific communication) run across all four topics but are rated only by your own teacher from in-class and practical work across the year; they never appear on the written paper and this hub does not attempt to simulate them.
Yes, with one adjustment. From 2022 onward the exam has used the current 180-mark format: four compulsory sections (A–D) worth 45 marks each, still the structure of the 2025 paper. The 2021 paper and earlier used an older 160-mark format: four parts (Part 1–4) worth 40 marks each. Both formats test the same four criteria in the same order, so older papers are still useful practice, but expect different per-question mark totals and question counts than a current-format paper.
There is no raw mark. Each of the eight criteria is rated A, B or C from internal and (for Criteria 5–8) external assessment, and TASC combines those ratings into one overall course award: SA, CA, HA or EA. Only after your award is finalised does TASC's Scaling Committee convert it into a numerical course score (2025 range 1.0–26.0) using Rasch analysis against every other student's results across all their courses. That course score, not the award itself, is what feeds your Tertiary Entrance Score and ATAR.
Knowing the course document is the first half. The other half is seeing how TASC actually asks it — every official paper for Chemistry is indexed by the same areas above.