CEnT-S CHEMISTRY TOPICS · EXAM BLUEPRINT

What to Focus & How to Prepare?

Complete syllabus breakdown, question-bank frequency analysis, difficulty rankings, solved sample problems and a 10-week study plan. Master the 10 chemistry questions in 20 minutes.

10 Chemistry Questions (10 Pts)20 Minutes Section TimerTopic Difficulty Rankings10-Week Study Schedule
Take Free Diagnostic TestView all CEnT-S topics
10 MCQsChemistry Questions
10 Core TopicsIn the CISIA Syllabus
2 minAverage Time per Question
AppliedEveryday Chemistry Included

Chemistry is the fourth section of CEnT-S: 10 questions in 20 minutes. Questions are short and conceptual; when a calculation appears it is a one-step mole or concentration ratio.

Atomic structure, bonding and stoichiometry are constants. A topic specific to CEnT-S — and absent from IMAT — is applied chemistry: label reading, everyday chemistry, environment and safety.

Question distribution analysis

CEnT-S Chemistry Topics: Frequency

Which topics demand your deepest attention? Below is the topic breakdown from our CEnT-S question data:

TopicExam 1Exam 2Total
Matter, Mixtures & Solutions347
Atomic Structure, Bonding & Periodic Table325
Thermochemistry & Energy213
Acids, Bases & pH112
Kinetics & Catalysis—11
Redox & Electrochemistry1—1
Environmental Chemistry—11

*Question counts per topic in 2 CEnT-S past exams from our question bank; each exam has the full 10 Chemistry questions. Exams are numbered, not dated. These figures are derived from the past-exam question samples that have reached us; the samples may be incomplete or contain errors, and the topic mix can change from one exam session to the next. Treat them as a guide to priorities, not a prediction of your exam.

Key Takeaways

  • Atomic structure & periodic table is the most frequent block: particles, groups and trends.
  • Matter & solutions: phase changes, mixtures and concentration units come up every session.
  • Applied chemistry (galvanisation, ozone, everyday reactions) is unique to CEnT-S.
  • Calculations are rare and simple — conceptual precision earns most points.
Difficulty analysis

Topic Difficulty & Recommended Study Allocation

Not all topics require the same time investment. Some need extensive problem-solving practice, others rely on precise conceptual recall:

Hard
Reactions & Stoichiometry 1.5–2 weeks
Medium
Acids & Bases 1 week
Medium
Atomic Structure & Bonding 1 week
Medium
Thermodynamics & Kinetics 1 week
Medium
Compounds & Solutions 1 week
Medium
Redox 4–5 days
Medium
Organic Chemistry 4–5 days
Easy
Periodic Trends 3–4 days
Easy
Macroscopic Properties of Matter 3–4 days
Easy
Applied Chemistry 2–3 days

Not Sure Where to Begin Your Preparation?

Take the free CEnT-S diagnostic test: see your baseline in every section and get a personalised AI study plan.

Take Diagnostic Test
Official syllabus breakdown

CEnT-S Chemistry Topics: How Each Is Tested

A topic-by-topic look at the Chemistry section of the official CISIA CEnT-S syllabus:

01

Macroscopic Properties of Matter Easy

  • Particle model and states of matter; phase transitions.
  • Pure substances and mixtures; separation techniques.
  • Fundamental laws: Lavoisier, Proust, Gay-Lussac, Avogadro.

How it appears on CEnT-S: Definition items (fusion, sublimation) and conservation-of-mass reasoning.

02

Atomic Structure & Bonding Medium

  • Protons, neutrons, electrons; mass and atomic number.
  • Lewis structures; ionic, covalent and metallic bonds.
  • Intermolecular forces, VSEPR shapes and hybridisation.

How it appears on CEnT-S: Comparing particles, predicting bond type from electronegativity, and boiling-point comparisons via hydrogen bonding.

03

Periodic Trends Easy

  • Groups and periods; alkali metals, halogens, noble gases.
  • Quantum numbers, isotopes and electron configuration.
  • Electronegativity, atomic radius and ionisation energy trends.

How it appears on CEnT-S: ‘Which element is an alkali metal / halogen?’ and trend direction across a period and down a group.

04

Reactions & Stoichiometry Hard

  • Balancing equations.
  • Mole concept, mass–mole conversions, molar mass.
  • Limiting reactant and concentration units (M, N, % w/w).

How it appears on CEnT-S: One-step proportional calculations; identifying the limiting reactant before computing.

05

Thermodynamics & Kinetics Medium

  • Ideal gas laws.
  • Internal energy, enthalpy, entropy and Gibbs free energy.
  • Equilibrium constant, activation energy and catalysis.

How it appears on CEnT-S: Exothermic vs endothermic comparisons and ‘what does a catalyst change?’.

06

Compounds & Solutions Medium

  • IUPAC and traditional nomenclature.
  • Electrolytes and solubility.
  • Colligative properties.

How it appears on CEnT-S: Naming common acids/salts and predicting the behaviour of dissolved salts (e.g. pH of NaCl solution).

07

Acids & Bases Medium

  • Arrhenius and Brønsted–Lowry definitions; strength.
  • pH calculation for strong acids/bases.
  • Neutralisation and buffers.

How it appears on CEnT-S: Classifying compounds (HNO₃ is an acid) and quick pH from powers of ten.

08

Redox Medium

  • Oxidation states.
  • Oxidising and reducing agents.
  • Balancing redox reactions; galvanic protection.

How it appears on CEnT-S: Assigning oxidation numbers and recognising sacrificial protection (zinc on iron).

09

Organic Chemistry Medium

  • Carbon hybridisation and isomerism.
  • Alkanes, alkenes, alkynes, aromatics.
  • Alcohols, aldehydes, ketones, carboxylic acids, esters.

How it appears on CEnT-S: Recognising functional groups and naming simple molecules.

10

Applied Chemistry Easy

  • Measurement units and uncertainty.
  • Everyday chemistry and label reading.
  • Environmental issues and safety regulations.

How it appears on CEnT-S: Pollutants (ozone, CO₂), safety pictograms and household chemistry — unique to CEnT-S.

Official CISIA Syllabus

The full, official CEnT-S syllabus and test structure are published by CISIA:

cisiaonline.it — CEnT-S structure and syllabus
Solved exam problems

CEnT-S Chemistry Sample Questions & Elimination Tactics

See how CEnT-S chemistry questions are built and how disciplined elimination avoids the −0.25 penalty:

01Matter · Phase ChangesQuestion 1
What do we mean by fusion?
Pick an answer to see the explanation
02Atomic StructureQuestion 2
A proton and an electron have
Pick an answer to see the explanation
03Acids & NomenclatureQuestion 3
The chemical compound HNO3\mathrm{HNO_3} is
Pick an answer to see the explanation
Candidate trap analysis

5 Most Common Mistakes in CEnT-S Chemistry

Recurring conceptual and tactical errors that cost students crucial points:

01

Catalysts and yield

A catalyst lowers activation energy and speeds up both directions; it never changes yield or K.

02

Salt solutions are not always neutral

NaCl gives pH 7, but salts of weak acids or bases do not — know which ions hydrolyse.

03

Oxidation number exceptions

Oxygen is −1 in peroxides; hydrogen is −1 in metal hydrides; fluorine is always −1.

04

Celsius in gas laws

Always convert to Kelvin before using PV = nRT or any proportionality.

05

Skipping applied chemistry

Everyday and environmental chemistry is a CEnT-S-only topic and easy marks for prepared students.

Study roadmap

10-Week Strategic Study Roadmap

Weeks 1–2

Diagnostic & Foundations

Take a timed diagnostic; rebuild the Foundation topics marked ‘Easy’ and note every error type.

Weeks 3–5

Core Topics

Work through the ‘Medium’ and ‘Hard’ topics in the order of the frequency table; 20–30 targeted questions per topic.

Weeks 6–7

Mixed Practice

Mixed sets under section timing (2 min/question). Keep an error log: concept, reading or calculation.

Weeks 8–9

Full Mocks

One full 65-question CEnT-S mock per week with real section timers; review every wrong and every guessed answer.

Week 10

Final Polish

Re-do your error log, revise traps, and practise the skip-or-guess rule for the −0.25 penalty.

Other CEnT-S Section Guides