Question 1 · Both levels
Which statement best describes one mole of a substance? Take the Avogadro constant as 6.02 × 10²³ per mole.
The new Leaving Cert Chemistry
Students sitting Leaving Cert Chemistry in June 2027 are the first to be examined on the new specification: a written examination worth 60% and the Chemistry in Practice Investigation worth 40%.
26 weeks, 104 hours in all
Start with Section 2
Matter, atomic structure and the periodic table: 12.8 of your hours. It is 4 of the 30 questions on each of our practice papers, 13%.
| Section | Your hours | Share of the papers |
|---|---|---|
| Section 2: Matter, atomic structure and the periodic table | 12.8 | 13% |
| Section 3: The mole, stoichiometry and gases | 12.8 | 13% |
| Section 5: Hydrocarbons and organic reactions | 12.8 | 13% |
| Section 6: Thermochemistry and rates of reaction | 12.8 | 13% |
| Section 8: Acids, bases and volumetric analysis | 12.8 | 13% |
| Section 4: Bonding, intermolecular forces and shapes | 9.6 | 10% |
| Section 7: Chemical equilibrium | 9.6 | 10% |
| Section 1: Nature of science and investigating | 6.4 | 7% |
| Section 9: Electrochemistry and our chemical environment | 6.4 | 7% |
Week by week
- Week 1Section 2: Matter, atomic structure and the periodic table
- Week 2Section 2: Matter, atomic structure and the periodic table
- Week 3Section 2: Matter, atomic structure and the periodic table
- Week 4Section 2: Matter, atomic structure and the periodic table, Section 3: The mole, stoichiometry and gases
- Week 5Section 3: The mole, stoichiometry and gases
- Week 6Section 3: The mole, stoichiometry and gases
- Week 7Section 3: The mole, stoichiometry and gases, Section 5: Hydrocarbons and organic reactions
- Week 8Section 5: Hydrocarbons and organic reactions
- Week 9Section 5: Hydrocarbons and organic reactions
- Week 10Section 5: Hydrocarbons and organic reactions, Section 6: Thermochemistry and rates of reaction
- Week 11Section 6: Thermochemistry and rates of reaction
- Week 12Section 6: Thermochemistry and rates of reaction
- Week 13Section 6: Thermochemistry and rates of reaction, Section 8: Acids, bases and volumetric analysis
- Week 14Section 8: Acids, bases and volumetric analysis
- Week 15Section 8: Acids, bases and volumetric analysis
- Week 16Section 8: Acids, bases and volumetric analysis
- Week 17Section 4: Bonding, intermolecular forces and shapes
- Week 18Section 4: Bonding, intermolecular forces and shapes
- Week 19Section 4: Bonding, intermolecular forces and shapes, Section 7: Chemical equilibrium
- Week 20Section 7: Chemical equilibrium
- Week 21Section 7: Chemical equilibrium, Section 1: Nature of science and investigating
- Week 22Section 1: Nature of science and investigating
- Week 23Section 1: Nature of science and investigating, Section 9: Electrochemistry and our chemical environment
- Week 24Section 9: Electrochemistry and our chemical environment
- Week 25A timed multiple-choice practice paper and two written questions, then review every lost mark
- Week 26A timed multiple-choice practice paper and two written questions, then review every lost mark
| Written examination | 60%, Higher or Ordinary Level; the 2027 sample Higher Level papers are 2 hours 30 minutes and 300 marks |
|---|---|
| Chemistry in Practice Investigation | 40%, a common brief done in school and reported to the SEC in Year 2 of the course |
| Strands | The Nature of Science, Nature of Matter, Behaviour of Matter, Interactions of Matter, Matter in our World |
| First examined | June 2027 |
Five strands and three themes
The unifying strand, The Nature of Science, is about how science works and how to investigate. The four contextual strands are Nature of Matter, Behaviour of Matter, Interactions of Matter, and Matter in our World. Health, sustainability and technology run through all of them.
Higher and Ordinary Level
The specification prints some learning outcomes in bold. Ordinary Level covers the outcomes in normal type; Higher Level covers all of them, including the bold ones. In this course every question is marked Higher Level or both levels.
How this course is organised
We group the specification into nine sections, starting with investigating and the nature of science, with a lesson, practice and experiment questions in each.
Try 2 questions
Question 2 · Both levels
Which observation shows that vinegar is acidic?
Next step
Questions people ask
Is the new Chemistry specification examined in 2027?
Yes. It was introduced to fifth years in September 2025 and is examined for the first time in June 2027.
Is the Chemistry in Practice Investigation done at Higher or Ordinary Level?
Neither: it is a common brief, the same for every student. The written examination is set at Higher and Ordinary Level.
Are old past papers still useful?
For some topics, but the specification has changed, so check each question against the new learning outcomes.