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TCE Chemistry Level 4 (CHM415115) exam strategy: The 2026 guide

TCEChemistryStudy guide13 min read

How the 2026 TASC Chemistry Level 4 exam (CHM415115) works: a three-hour paper in four 45-minute sections, one for each of criteria 5 to 8, where calculations from every topic are assessed in the criterion 8 section. Award rules, worked examples for each criterion, common mistakes and a plan to 18 November.

Jump to a section
  1. The exam at a glance
  2. How the exam feeds your award
  3. Instructions worth rehearsing
  4. Worked examples for each criterion
  5. Common mistakes
  6. Eight weeks to 18 November

The exam at a glance

2026 TCE Chemistry Level 4 exam (CHM415115)

Wednesday 18 November 2026, 1.30 pm. A three-hour written exam assessing criteria 5, 6, 7 and 8. In the 2024 paper: 15 minutes preparation time, then four sections of 45 marks and about 45 minutes each, one per criterion. Approved scientific calculator and the Chemistry Information Sheet allowed throughout.

The criteria come from the TASC course document, the section layout and instructions from the 2024 TASC paper, and the date from the 2026 TASC written exam timetable. TASC's current external assessment specifications on the course page are the authoritative guide to the 2026 paper.

Section (2024 paper) Criterion Focus
A 5 Fundamental principles and theories of electrochemistry
B 6 Thermochemistry, kinetics and equilibrium
C 7 Properties and reactions of organic and inorganic matter
D 8 Logical processes to solve quantitative chemical problems

The course document adds a crucial detail: calculations from criteria 5, 6 and 7 (for example Faraday's laws) are examined externally as part of criterion 8. So Sections A to C lean towards concepts, equations and explanations, while Section D is where the numbers are.

How the exam feeds your award

Your award is decided by TASC from 12 ratings: 8 from internal assessment and 4 from the exam. The course document sets minimum requirements, including:

Award Minimum ratings Of which from the exam
Exceptional Achievement (EA) 10 A, 2 B 3 A, 1 B
High Achievement (HA) 4 A, 5 B, 3 C 1 A, 2 B, 1 C
Commendable Achievement (CA) 6 B, 5 C 2 B, 2 C
Satisfactory Achievement (SA) 10 C 3 C

Each section gives one rating, so spend 45 minutes on each and do not leave any section thin.

Instructions worth rehearsing

The 2024 paper told students to show working in numerical answers, because no marks can be given for incorrect answers unless details of the working are shown. For "show that" questions it asked students to calculate their own value to appropriate significant figures and use it in later parts, or to use the given value if they could not find it. That is a gift: never abandon later parts because an earlier calculation went wrong.

Worked examples for each criterion

The criteria 5 to 8 deep dive covers each area in detail.

Criterion 5: a galvanic cell

A cell is made from a copper electrode in Cu2+(aq)\text{Cu}^{2+}(aq) (E°=+0.34E° = +0.34 V) and a silver electrode in Ag+(aq)\text{Ag}^+(aq) (E°=+0.80E° = +0.80 V).

Silver ions are the stronger oxidiser, so they are reduced at the cathode: Ag+(aq)+e−→Ag(s)\text{Ag}^+(aq) + e^- \rightarrow \text{Ag}(s). Copper is oxidised at the anode: Cu(s)→Cu2+(aq)+2e−\text{Cu}(s) \rightarrow \text{Cu}^{2+}(aq) + 2e^-.

E°cell=0.80−0.34=0.46E°_\text{cell} = 0.80 - 0.34 = 0.46 V. Cell diagram, anode on the left: Cu(s) ∣ Cu2+(aq) ∣∣ Ag+(aq) ∣ Ag(s)\text{Cu}(s)\,|\,\text{Cu}^{2+}(aq)\,||\,\text{Ag}^+(aq)\,|\,\text{Ag}(s).

Criterion 6: Hess's law

Given C(s)+O2(g)→CO2(g)\text{C}(s) + \text{O}_2(g) \rightarrow \text{CO}_2(g), ΔH=−394\Delta H = -394 kJ mol−1^{-1}, and CO(g)+12O2(g)→CO2(g)\text{CO}(g) + \tfrac{1}{2}\text{O}_2(g) \rightarrow \text{CO}_2(g), ΔH=−283\Delta H = -283 kJ mol−1^{-1}, find ΔH\Delta H for C(s)+12O2(g)→CO(g)\text{C}(s) + \tfrac{1}{2}\text{O}_2(g) \rightarrow \text{CO}(g).

Keep the first equation and reverse the second (changing the sign): ΔH=−394+283=−111\Delta H = -394 + 283 = -111 kJ mol−1^{-1}.

Criterion 7: addition to an asymmetric alkene

But-1-ene reacts with hydrogen bromide. Name the possible products.

HBr adds across the double bond, and because but-1-ene is asymmetric there are two possible isomers: 2-bromobutane (Br on carbon 2) and 1-bromobutane (Br on carbon 1). The course asks you to identify the possible isomers, so name both.

Criterion 8: limiting reagent and gas volume

5.00 g of magnesium is added to 100 mL of 1.00 mol L−1^{-1} hydrochloric acid: Mg(s)+2HCl(aq)→MgCl2(aq)+H2(g)\text{Mg}(s) + 2\text{HCl}(aq) \rightarrow \text{MgCl}_2(aq) + \text{H}_2(g). Find the volume of hydrogen at SLC.

n(Mg)=5.0024.31=0.206n(\text{Mg}) = \dfrac{5.00}{24.31} = 0.206 mol. n(HCl)=1.00×0.100=0.100n(\text{HCl}) = 1.00 \times 0.100 = 0.100 mol, which reacts with only 0.0500 mol of Mg, so HCl is limiting.

n(H2)=0.1002=0.0500n(\text{H}_2) = \dfrac{0.100}{2} = 0.0500 mol, and V=0.0500×24.5=1.23V = 0.0500 \times 24.5 = 1.23 L at SLC.

Common mistakes

Where Chemistry ratings slip
  • Leaving later parts blank after an early calculation error. Use the given "show that" value and carry on.
  • Writing cell diagrams with the cathode on the left, or putting electrons on the wrong side of half-equations.
  • Forgetting to reverse the sign of ΔH\Delta H when reversing an equation in Hess's law.
  • Naming only one product when an asymmetric molecule adds to an alkene.
  • Missing the limiting reagent step, or using the wrong molar volume (SLC 24.5 L, STP 22.4 L).
  • Answers without units or with unjustified significant figures.

Eight weeks to 18 November

  1. Weeks of 21 and 28 September: Criterion 5: redox, half-equations, cells, electrolysis and corrosion.
  2. Weeks of 5 and 12 October: Criterion 6: thermochemistry and Hess's law, rates, equilibrium, Kc and acids.
  3. Week of 19 October: Criterion 7: organic families and reactions, spectroscopy, periodic trends and gases.
  4. Week of 26 October: Criterion 8: stoichiometry, titrations, gas laws, yield and Faraday calculations.
  5. Weeks of 2 and 9 November: Past TASC papers under timed conditions, 45 minutes per section, then targeted revision of your weakest criterion.

Test yourself with the mixed exam-style quiz and the criteria 5 to 8 quiz.

Sources & how we know this

  • chemistry
  • tce
  • tce-chemistry
  • exam-strategy
  • electrochemistry
  • equilibrium
  • organic-chemistry
  • stoichiometry
  • year-12
  • 2026

Based on the official TASC course document. Not yet individually reviewed by a person; always check TASC and your school's materials for current rules.

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