NCEA Level 2 Chemistry: the three externals, the exam and practice

NCEA Level 2 Chemistry standards

That is 13 external credits and up to 13 internal credits. NZQA's past exams and assessment schedules are on its Chemistry past exams page.

The NCEA Level 2 Chemistry exam

According to NZQA's 2027 assessment specifications, the exam is on printed paper and comes with a resource booklet holding the formulae you need, such as n = cV, and a periodic table with molar masses. An approved scientific or graphics calculator is required. Show all working, round to three significant figures and include units.

What each external covers

Bonding, structure, properties and energy changes (91164)

Ionic, covalent and metallic bonding; intermolecular forces; Lewis structures, shapes and polarity of simple molecules; molecular, ionic, metallic and covalent network substances and their properties; and exothermic and endothermic reactions, including enthalpy changes for different amounts, changes of state and bond making and breaking.

Organic compounds (91165)

Alkanes, alkenes, alkynes, haloalkanes, primary amines, alcohols and carboxylic acids: naming, structural and cis-trans isomers, classifying alcohols and haloalkanes as primary, secondary or tertiary, physical properties, and reactions such as addition to alkenes (including major and minor products), substitution and polymerisation.

Chemical reactivity (91166)

Rates of reaction explained with collision theory and activation energy; equilibrium, including the effect of changing conditions and the equilibrium constant Kc; and acids and bases, including pH.

Worked examples

Energy changes: how much heat?

Methane burns with ΔrH = −890 kJ mol⁻¹. How much energy is released when 8.0 g burns? Moles of methane = 8.0 ÷ 16.0 = 0.500 mol, so the energy released is 0.500 × 890 = 445 kJ.

Equilibrium: the equilibrium constant

For N₂O₄ ⇌ 2NO₂, the equilibrium concentrations are [N₂O₄] = 0.040 mol L⁻¹ and [NO₂] = 0.020 mol L⁻¹.

Organic: which isomer?

But-2-ene has cis and trans isomers, because each carbon of its double bond carries two different groups; but-1-ene does not. When propene reacts with HBr, the major product is 2-bromopropane, because the hydrogen adds to the carbon that already has more hydrogens.

Practise bond energies from our Chemical Bonding course, then press Mark to check your answer in the course:

Grades, credits and endorsements

Every NCEA standard is graded Not Achieved, Achieved, Merit or Excellence, and earns its credits at whatever grade you reach. Achieved shows you meet the standard, Merit shows deeper understanding, and Excellence shows it applied to harder, unfamiliar problems.

• The certificate: NCEA Level 2 needs 60 credits at Level 2 or above, plus the 20-credit literacy and numeracy co-requisite, which you can gain any time before you leave school. Since 2024 you can no longer carry 20 credits over from the level below.
• Certificate endorsement: 50 credits at Merit or better gives a Merit endorsement; 50 at Excellence gives an Excellence endorsement.
• Course endorsement: 14 or more credits at Merit or Excellence in one subject in one year, with at least 3 from internal and 3 from external standards in most subjects.

Use the daily paper as a practice exam

Uni-Sine publishes a free daily paper on the NCEA Level 2 Chemistry track. It is a short timed paper: 8 questions worth 25 to 35 marks, marked instantly, with worked answers. It is not a full NCEA exam and it is not written by NZQA, so treat it as a quick daily practice test alongside NZQA's past papers.

• What it covers well: bonding and molecular shapes, intermolecular forces, enthalpy changes, alkanes, alkenes, haloalkanes and alcohols, isomerism, rates and equilibria, which support all three externals.
• What it does not cover: acids, bases and pH, amines and carboxylic acids in depth, and the internals, including redox and the practical investigations. It also includes Hess's law, electron configuration and periodicity, which go beyond NCEA Level 2.

A good routine is one daily paper under timed conditions, then a careful look at every mark you dropped, then one NZQA past paper a week in the weeks before the exam.

NCEA changes for 2026, 2027 and beyond

NCEA still applies in 2026 and 2027, so the standards on this page are the ones you will sit. New Level 2 standards are due to be fully in place by 2028, and in 2029 a new New Zealand Certificate of Education (NZCE) replaces NCEA Level 2 for Year 12. The Government agreed the structure of the new qualification system on 26 March 2026, and the Ministry of Education confirmed further details and the timeline on 16 May 2026.

Common mistakes in NCEA Level 2 Chemistry

• Breaking covalent bonds when a substance melts. Simple molecular substances melt by overcoming weak intermolecular forces, not covalent bonds.
• Wrong sign on ΔH. Exothermic reactions release energy and have negative ΔH.
• Including solids or water in Kc. Only species in solution or gases appear in the expression for homogeneous systems.
• Missing the major product. For addition to an asymmetric alkene, state which product is major and why.

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