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Chemistry
15 sections available · 44 chapters available
Free Chemistry study notes for Senior Secondary (HKDSE) students. Each chapter breaks down a key concept with examples and practice prompts you can turn into AI drills in the thinka app.
Planet Earth
Atmosphere composition & testing O₂
Seawater composition, salt extraction, electrolysis, water isolation
Rocks & minerals, separation techniques: distillation, crystallization, filtration
Microscopic World I
Atomic structure, periodic trends
Ionic, covalent, metallic bonding, giant structures
Molecular shapes, formulae; link macro–micro
Chemical formulae; link macro–micro
Metals
Metal ores, finite resource, recycling
Reactivity series, displacement, extraction methods
Corrosion, anodisation, social–environmental implications
Acids and Bases
Common acids/alkalis; H⁺(aq) concept; pH determination
Strong vs weak, dissociation extent
Titration techniques; volumetric analysis & stoichiometry
Fossil Fuels & Carbon Compounds
Sources: coal, petroleum, natural gas
Fractional distillation, uses, pollution effects
Homologous series; naming; addition polymerisation
Microscopic World II
Bond polarity by electronegativity
Intermolecular forces: Van der Waals’, hydrogen bonds
Molecular shapes (e.g. CH₄, NH₃, H₂O, BF₃)
Redox Reactions, Chemical Cells & Electrolysis
Oxidation numbers, redox reactions
Zinc–carbon cell, inert electrode cells, fuel cells
Electroplating, copper purification, environmental links
Chemical Reactions and Energy
Enthalpy changes; Hess’s Law; energy cycles
Stoichiometric calculations involving energy terms
Rate of Reaction
Reaction monitoring methods (titration, gas volume, temperature)
Instantaneous vs average rates; molar gas volumes
Collision theory, activation energy, catalysts
Chemical Equilibrium
Reversible reactions; dynamic equilibrium
Equilibrium constant (Kc); Le Chatelier’s Principle
Effects of temperature and concentration
Chemistry of Carbon Compounds
Homologous series (alkanes, alkenes, haloalkanes, alcohols, aldehydes, ketones, acids, esters, amides, amines)
Isomerism: structural, cis‑trans, enantiomerism
Reactions: substitution, addition, oxidation, esterification, hydrolysis; inter-conversions
Important compounds: aspirin, detergents, nylon, polyesters
Patterns in the Chemical World
Periodic trends: oxide acid-base character
Transition metals: coloured ions, variable oxidation states, catalysis
Industrial Chemistry
Kinetics, activation energy; Arrhenius equation
Catalysts; green chemistry (atom economy, pollution control)
Materials Chemistry
Natural polymers (cellulose, chitin)
Synthetic polymers; plastics, liquid crystals, nanomaterials
Comparison: metals vs alloys; composites
Analytical Chemistry
Cation tests (flame test), gas tests, purity tests
Volumetric (titration) quantitative analysis
Instrumental methods, forensic, environmental, clinical applications
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