NCEA Level 2 Chemistry resource booklet: periodic table and formulae

Formula sheet

The card below opens today's Level 2 Chemistry paper with the sheet in the drawer. The contents follow in our own layout. This is the 2025 booklet, the latest NZQA has published. NZQA's 2026 specification says the booklet will contain relevant formulae, for example n = cV, and a copy of the periodic table, and that it can be found on NZQA's Chemistry subject page, so you can practise with it before the exam.

Bonding, structure, properties and energy changes (91164)

Chemical reactivity (91166)

Periodic table

Page 3 is a periodic table of the elements. Each box shows the atomic number, the symbol and the molar mass in g mol⁻¹, and the groups are numbered 1 to 18. NZQA's specification says to use the molar masses given with the question, or on the periodic table, so do not take them from memory or from another table.

What is not on the sheet

• Bond energies and other data. The enthalpy line needs bond energies, which come with the question. NZQA says any context-specific formulae will also be provided in the exam.
• Organic chemistry. 91165 has no formulae, so naming, functional groups and reactions are all recall.
• Rate and equilibrium formulae. The booklet has no line for rates of reaction or for an equilibrium constant, so you cannot look either up.
• Symbols and nomenclature. NZQA says the reference sheet on quantities, units, symbols and nomenclature is not provided in the exam. IUPAC conventions apply to names, spelling and formatting.
• Which formula to use. The sheet does not say when to use n = cV and when n = m/M.

How to use the sheet in the exam

1. Write the balanced equation and the quantities given, with units.
2. Decide whether the question is about a solution, which means n = cV, or a solid, which means n = m/M.
3. For pH questions, say what [H₃O⁺] is first, then take the log.
4. Give numerical answers to three significant figures with the correct unit, as NZQA expects at Level 2.

Energy changes: bond energies

Methane burns in oxygen: CH₄ + 2O₂ → CO₂ + 2H₂O. A question gives these bond energies in kJ mol⁻¹: C-H 413, O=O 498, C=O 805, O-H 464. Bonds broken are 4 C-H and 2 O=O. Bonds formed are 2 C=O and 4 O-H. The sheet line subtracts the formed from the broken:

The negative sign says the reaction releases energy. Practise this in our Chemical Bonding course, then press Mark to check your answer there:

Chemical reactivity: pH and the water constant

The pH of a solution is 12.40. Use the second pH line to find the hydronium concentration, then the water constant to find the hydroxide concentration:

The line n = cV takes a volume in litres. For 40.0 mL of that solution, n = 0.0251 × 0.0400 = 1.00 × 10⁻³ mol of hydroxide ions.

The Level 2 sheet and the other chemistry sheets

The Level 3 Chemistry booklet adds the heat, Ka, pKa and Ks lines, and nine complex ions. At Level 1 the periodic table in the Chemistry and Biology booklet shows symbols and atomic numbers but no molar masses. For how the three Level 2 standards work, see the NCEA Level 2 Chemistry guide.

Exam answers

The answers and a worked mark scheme come with today's paper once it is marked. Sit the paper with the booklet open beside you, mark it, and the worked answers show which line each question wanted. We do not publish official or past paper answers. Every question on the daily paper is our own.

Use the sheet with today's paper

Uni-Sine publishes a free daily paper on the NCEA Level 2 Chemistry track. It is a short timed paper of 8 questions worth 25 to 35 marks, not a full NCEA exam, and it is not written by NZQA. Open the sheet from the paper itself, so the periodic table and formulae are one click away as they are in the exam.

Common mistakes with the Level 2 Chemistry sheet

• Using mL in n = cV. Convert to litres first.
• Adding the bond energies the wrong way round. It is broken minus formed.
• Forgetting the minus sign in pH = −log[H₃O⁺]. A pH cannot come out as −3 for a concentration of 10⁻³.
• Using the wrong molar mass. Take it from the booklet's table.

Read next

New Zealand · NCEA Level 3NCEA Level 3 Chemistry formula sheet and periodic tableThe NCEA Level 3 Chemistry formula sheet: the pH, Ka, Ks and enthalpy formulae, the nine complex ions, the periodic table and worked examples.