What do we mean by fusion?
Elige una respuesta para ver la explicación
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.
Análisis de la distribución de preguntas
Temas de Chemistry de CEnT-S: frecuencia
¿Qué temas requieren más atención? Este es el desglose por temas a partir de nuestros datos de preguntas de CEnT-S:
| Tema | Total | |
|---|---|---|
| Matter, Mixtures & Solutions | 7 | |
| Atomic Structure, Bonding & Periodic Table | 5 | |
| Thermochemistry & Energy | 3 | |
| Acids, Bases & pH | 2 | |
| Kinetics & Catalysis | 1 | |
| Redox & Electrochemistry | 1 | |
| Environmental Chemistry | 1 |
*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.
Ideas clave
- 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.
Análisis de dificultad
Dificultad de los temas y reparto de estudio recomendado
No todos los temas exigen el mismo tiempo. Algunos requieren mucha práctica resolviendo problemas; otros dependen de recordar con precisión conceptos concretos:
Difícil
Reactions & Stoichiometry 1.5–2 weeksMedio
Acids & Bases 1 weekMedio
Atomic Structure & Bonding 1 weekMedio
Thermodynamics & Kinetics 1 weekMedio
Compounds & Solutions 1 weekMedio
Redox 4–5 daysMedio
Organic Chemistry 4–5 daysFácil
Periodic Trends 3–4 daysFácil
Macroscopic Properties of Matter 3–4 daysFácil
Applied Chemistry 2–3 days¿No sabes por dónde empezar tu preparación?
Haz el test diagnóstico gratuito de CEnT-S: conoce tu nivel de partida en cada sección y recibe un plan de estudio personalizado con IA.
Hacer el test diagnósticoDesglose del temario oficial
Temas de Chemistry de CEnT-S: cómo se evalúa cada uno
Un repaso tema por tema de la sección de Chemistry del official CISIA CEnT-S syllabus:
01
Macroscopic Properties of Matter Fácil
- Particle model and states of matter; phase transitions.
- Pure substances and mixtures; separation techniques.
- Fundamental laws: Lavoisier, Proust, Gay-Lussac, Avogadro.
Cómo aparece en CEnT-S: Definition items (fusion, sublimation) and conservation-of-mass reasoning.
02
Atomic Structure & Bonding Medio
- Protons, neutrons, electrons; mass and atomic number.
- Lewis structures; ionic, covalent and metallic bonds.
- Intermolecular forces, VSEPR shapes and hybridisation.
Cómo aparece en CEnT-S: Comparing particles, predicting bond type from electronegativity, and boiling-point comparisons via hydrogen bonding.
03
Periodic Trends Fácil
- Groups and periods; alkali metals, halogens, noble gases.
- Quantum numbers, isotopes and electron configuration.
- Electronegativity, atomic radius and ionisation energy trends.
Cómo aparece en CEnT-S: ‘Which element is an alkali metal / halogen?’ and trend direction across a period and down a group.
04
Reactions & Stoichiometry Difícil
- Balancing equations.
- Mole concept, mass–mole conversions, molar mass.
- Limiting reactant and concentration units (M, N, % w/w).
Cómo aparece en CEnT-S: One-step proportional calculations; identifying the limiting reactant before computing.
05
Thermodynamics & Kinetics Medio
- Ideal gas laws.
- Internal energy, enthalpy, entropy and Gibbs free energy.
- Equilibrium constant, activation energy and catalysis.
Cómo aparece en CEnT-S: Exothermic vs endothermic comparisons and ‘what does a catalyst change?’.
06
Compounds & Solutions Medio
- IUPAC and traditional nomenclature.
- Electrolytes and solubility.
- Colligative properties.
Cómo aparece en CEnT-S: Naming common acids/salts and predicting the behaviour of dissolved salts (e.g. pH of NaCl solution).
07
Acids & Bases Medio
- Arrhenius and Brønsted–Lowry definitions; strength.
- pH calculation for strong acids/bases.
- Neutralisation and buffers.
Cómo aparece en CEnT-S: Classifying compounds (HNO₃ is an acid) and quick pH from powers of ten.
08
Redox Medio
- Oxidation states.
- Oxidising and reducing agents.
- Balancing redox reactions; galvanic protection.
Cómo aparece en CEnT-S: Assigning oxidation numbers and recognising sacrificial protection (zinc on iron).
09
Organic Chemistry Medio
- Carbon hybridisation and isomerism.
- Alkanes, alkenes, alkynes, aromatics.
- Alcohols, aldehydes, ketones, carboxylic acids, esters.
Cómo aparece en CEnT-S: Recognising functional groups and naming simple molecules.
10
Applied Chemistry Fácil
- Measurement units and uncertainty.
- Everyday chemistry and label reading.
- Environmental issues and safety regulations.
Cómo aparece en 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 syllabusProblemas de examen resueltos
Preguntas de ejemplo de Chemistry de CEnT-S y tácticas de eliminación
Descubre cómo se construyen las preguntas de chemistry de CEnT-S y cómo una eliminación disciplinada evita la penalización de −0.25:
A proton and an electron have
Elige una respuesta para ver la explicación
The chemical compound is
Elige una respuesta para ver la explicación
Análisis de trampas del examen
Los 5 errores más comunes en Chemistry de CEnT-S
Errores conceptuales y tácticos recurrentes que les cuestan puntos decisivos a los estudiantes:
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.
Hoja de ruta de estudio
Hoja de ruta estratégica de estudio de 10 semanas
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.