Chemistry Syllabus 0653 Syllabus 2025-2027

Chemistry Syllabus 0653 Syllabus 2025-2027- Chemistry

The official CIE syllabus can be found here. It is best to always refer to the original syllabus. *=extended material

 

C1. States of matter

·       State the distinguishing properties of solids, liquids and gases

·       Describe the structure of solids, liquids and gases in terms of particle separation, arrangement and motion

·       Describe the changes of state in terms of melting, boiling, evaporation, freezing and condensation

·       Describe the effects of temperature and pressure on the volume of a gas

·       Explain changes of state in terms of kinetic particle theory *

 

C2. Atoms, elements and compounds

2.1Elements, compounds and mixtures

·       Describe the differences between elements, compounds and mixtures

 

2.2 Atomic structure and the Periodic Table

·       Describe the structure of the atom as a central nucleus containing neutrons and protons, surrounded by electrons in shells

·       State the relative charges and relative masses of a proton, neutron and an electron

·       Define proton number/atomic number -number of protons in the nucleus of an atom

·       Define mass number/nucleon number as the total number of protons and neutrons in the nucleus of an atom

·       Determine the electronic configuration of elements with proton number 1 to 20

State that:

o   Group VIII noble gases have a full outer shell

o   the number of outer-shell electrons is equal to group number in Groups I-VII

o   the number of occupied electron shells is equal to the period number

 

2.3 Ions and ionic bonds

·       Describe the formation of positive ions, known as cations, and negative ions, known as anions

·       State that an ionic bond is a strong electrostatic attraction between oppositely charged ions

·       Describe the formation of ionic bonds between elements from Group I and Group VII, including the use of dot-and-cross diagrams

·       Describe the formation of ionic bonds between ions of metallic and non-metallic elements, including the use of dot-and-cross diagrams*

·       Describe the properties of ionic compounds: (a) high melting points and boiling points (b) good electrical conductivity when aqueous or molten and poor when solid (c) generally soluble in water

·       Describe the giant lattice structure of ionic compounds as a regular arrangement of alternating positive and negative ions, exemplified by sodium chloride*

2.4 Simple molecules and covalent bonds

·       State that a covalent bond is formed when a pair of electrons is shared between two atoms leading to noble gas electronic configurations 

·       Describe the formation of covalent bonds in simple molecules, including H2, Cl 2, H2O, CH4, NH3 and HCl. Use dot-andcross diagrams to show the electronic configurations in these molecules

·       Describe the formation of covalent bonds in simple molecules, including CH3OH, C2H4, O2, CO2 and N2. Use dot-and-cross diagrams to show the electronic configurations in these molecules*

·       Describe the properties of simple molecular compounds: (a) low melting points and boiling points (b) poor electrical conductivity

 

C3. Stoichiometry

3.1 Formulas

·       State the formulas of the elements and compounds named in the subject content

·       Define the molecular formula of a compound as the number and type of atoms in one molecule

·       Deduce the formula of a simple molecular compound from the relative numbers of atoms present in a model or a diagrammatic representation

·       Deduce the formula of an ionic compound from the relative numbers of the ions present in a model or a diagrammatic representation or from the charges on the ions*

·       Construct word equations to show how reactants form products

·       Balance and interpret simple symbol equations, including state symbols

·       Construct symbol equations with state symbols, including ionic equations *

 

C4. Electrochemistry

4.1 Electrolysis

·       Define electrolysis as the decomposition of an ionic compound, when molten or in aqueous solution, by the passage of an electric current

·       Identify in simple electrolytic cells: (a) the anode as the positive electrode (b) the cathode as the negative electrode (c) the electrolyte as the molten or aqueous substance that undergoes electrolysis

·       Identify the products formed at the electrodes and describe the observations, made during the electrolysis of: (a) molten lead(II) bromide (b) concentrated aqueous sodium chloride (c) dilute sulfuric acid using inert electrodes made of platinum or carbon/graphite

·       State that metals or hydrogen are formed at the cathode and that non-metals (other than hydrogen) are formed at the anode *

·       Predict the identity of the products at each electrode for the electrolysis of a binary compound in the molten state *

 

·       C5. Chemical energetics

5.1 Exothermic and endothermic reactions

·       State that an exothermic reaction transfers thermal energy to the surroundings leading to an increase in the temperature of the surroundings

·       State that an endothermic reaction takes in thermal energy from the surroundings leading to a decrease in the temperature of the surroundings

·       Interpret reaction pathway diagrams showing exothermic and endothermic reactions

·       Define activation energy, Ea, as the minimum energy that colliding particles must have to react *

·       Draw and label reaction pathway diagrams for exothermic and endothermic reactions using information provided, to include: (a) reactants (b) products (c) overall energy change of reaction (d) activation energy, Ea *

·       State that bond breaking is an endothermic process and bond making is an exothermic process*

 

·       C6. Chemical reactions

6.1 Physical and chemical changes

·       Identify physical and chemical changes, and understand the differences between them

 

6.2 Rate of reaction

·       Describe the effect on the rate of reaction of: (a) changing the concentration of solutions (b) changing the surface area of solids (c) changing the temperature           (d) adding or removing a catalyst

·       Explain the effect on the rate of reaction of: (a) changing the concentration of solutions (b) changing the surface area of solids (c) changing the temperature (d) adding or removing a catalyst using collision theory *

·       State that a catalyst increases the rate of a reaction and is unchanged at the end of a reaction

·       Describe practical methods for investigating the rate of a reaction including change in mass of a reactant or product and the formation of a gas

·       Interpret data, including graphs, from rate of reaction experiments

·       Describe collision theory in terms of: (a) number of particles per unit volume (b) frequency of collisions between particles (c) kinetic energy of particles (d) activation energy, Ea *

6.3 Redox

·       Define redox reactions as involving simultaneous oxidation and reduction

·       Define oxidation as gain of oxygen and reduction as loss of oxygen

·       Identify redox reactions as reactions involving gain and loss of oxygen

·       Identify oxidation and reduction in redox reactions. (Oxidation number limited to its use to name ions, e.g. iron(II), iron(III), copper(II).)

 

·       C7. Acids, bases and salts

7.1 The characteristic properties of acids and bases

·       Describe the characteristic properties of acids in terms of their reactions with: (a) metals (b) bases (c) carbonates

·       Describe acids in terms of their effect on the indicators: (a) litmus (b) methyl orange

·       State that bases are oxides or hydroxides of metals and that alkalis are soluble bases

·       Describe the characteristic properties of bases in terms of their reactions with acids

·       Describe alkalis in terms of their effect on the indicators: (a) litmus (b) methyl orange

·       Describe how to compare neutrality, relative acidity and relative alkalinity in terms of colour and pH using universal indicator

 

7.2 Oxides

·       Classify oxides as either acidic, including SO2 and CO2, or basic, including CuO and CaO, related to metallic and non-metallic character

 

7.3 Preparation of salts

·       Describe the preparation, separation and purification of soluble salts by reaction of an acid with: (a) an alkali by titration (b) excess metal (c) excess insoluble base (d) excess insoluble carbonate (candidates do not need to know general solubility rules for salts)

·       Describe the preparation of insoluble salts by precipitation (candidates do not need to know general solubility rules for salts) *

 

·       C8. The Periodic Table

8.1 The Periodic Table

·       Describe the Periodic Table as an arrangement of elements in periods and groups and in order of increasing proton number/atomic number

·       Describe the change from metallic to non-metallic character across a period

·       Identify trends in groups, given information about the elements *

 

8.2 Group I properties

·       Describe the Group I alkali metals, lithium, sodium and potassium, as relatively soft metals with general trends down the group, limited to: (a) decreasing melting point (b) increasing density (c) increasing reactivity with water

·       Predict the properties of other elements in Group I, given information about the elements *

 

8.3 Group VII properties

·       Describe the Group VII halogens, chlorine, bromine and iodine, as diatomic non-metals with general trends down the group, limited to: (a) increasing density (b) decreasing reactivity

·       State the appearance of the halogens at room temperature and pressure, r.t.p., as: (a) chlorine, a pale yellow-green gas (b) bromine, a red-brown liquid (c) iodine, a grey-black solid

·       Describe and explain the displacement reactions of halogens with other halide ions

·       Predict the properties of other elements in Group VII, given information about the elements *

 

8.4 Transition elements

·       Describe the transition elements as metals that: (a) have high densities (b) have high melting points (c) form coloured compounds (d) often act as catalysts as elements and in compounds

 

8.5 Noble gases

·       Describe the Group VIII noble gases as unreactive, monatomic gases and explain this in terms of electronic configuration

 

·       C9. Metals

9.1 Properties of metals

·       Compare the general physical properties of metals and non-metals, including: (a) thermal conductivity (b) electrical conductivity (c) malleability and ductility (d) melting points and boiling points

·       Describe the general chemical properties of metals, limited to their reactions with: (a) dilute acids (b) cold water and steam

 

9.2 Uses of metals

·       Describe the uses of metals in terms of their physical properties, including: (a) aluminium in the manufacture of aircraft because of its low density (b) aluminium in the manufacture of overhead electrical cables because of its low density and good electrical conductivity (c) aluminium in food containers because of its resistance to corrosion (d) copper in electrical wiring because of its good electrical conductivity

 

9.3 Alloys and their properties

·       Describe alloys as mixtures of a metal with other elements, including: (a) brass as a mixture of copper and zinc (b) stainless steel as a mixture of iron and other elements such as chromium, nickel and carbon

·       State that alloys can be harder and stronger than the pure metals and are more useful

·       Describe the use of alloys in terms of their physical properties, including stainless steel in cutlery because of its hardness and resistance to rusting

·       Identify representations of alloys from diagrams of structure

·       Explain in terms of structure how alloys can be harder and stronger than the pure metals because the different sized atoms in alloys mean the layers can no longer slide over each other*

 

9.4 Reactivity series

·       State the order of the reactivity series as: potassium, sodium, calcium, magnesium, aluminium, carbon, zinc, iron, hydrogen, copper, silver, gold

·       Describe the reactions, if any, of: (a) potassium, sodium and calcium with cold water (b) magnesium with steam (c) magnesium, zinc, iron, copper, silver and gold with dilute hydrochloric acid and explain these reactions in terms of the position of the metals in the reactivity series

·       Deduce an order of reactivity from a given set of experimental results

 

9.5 Corrosion of metals

·       State the conditions required for the rusting of iron (presence of oxygen and water)

·       State some common barrier methods, including painting, greasing and coating with plastic

·       Describe how barrier methods prevent rusting by excluding oxygen and water

 

9.5 Extraction of metals

·       Describe the ease in obtaining metals from their ores, related to the position of the metal in the reactivity series

·       State that iron from hematite is extracted by reduction of iron(III) oxide in the blast furnace

·       State that main ore of aluminium is bauxite and that aluminium is extracted by electrolysis

·       Describe the extraction of iron from hematite in the blast furnace, limited to: (a) the burning of carbon (coke) to provide heat and produce carbon dioxide C + O2 → CO2 (b) the reduction of carbon dioxide to carbon monoxide C + CO2 → 2CO (c) the reduction of iron(III) oxide by carbon monoxide Fe2O3 + 3CO → 2Fe + 3CO2 *

 

 

·       C10. Chemistry and the Environment

10.1 Water

·       Describe chemical tests for the presence of water using anhydrous cobalt(II) chloride and anhydrous copper(II) sulfate

·       State that distilled water is used in practical chemistry rather than tap water because it contains fewer chemical impurities

·       Describe the treatment of the domestic water supply in terms of: (a) sedimentation and filtration to remove solids (b) use of carbon to remove tastes and odours (c) chlorination to kill microbes

 

10.2 Air quality and climate

·       State the composition of clean, dry air as approximately 78% nitrogen, N2, 21% oxygen, O2, and the remainder as a mixture of noble gases and carbon dioxide, CO2

·       State the source of each of these air pollutants, limited to: (a) carbon dioxide from the complete combustion of carbon-containing fuels (b) carbon monoxide and particulates from the incomplete combustion of carboncontaining fuels (c) methane from the decomposition of vegetation and waste gases from digestion in animals (d) oxides of nitrogen from car engines (e) sulfur dioxide from the combustion of fossil fuels which contain sulfur compounds

·       State the adverse effect of these air pollutants, limited to: (a) carbon dioxide: higher levels of carbon dioxide leading to increased global warming, which leads to climate change (b) carbon monoxide: toxic gas (c) particulates: increased risk of respiratory problems and cancer (d) methane: higher levels of methane leading to increased global warming, which leads to climate change (e) oxides of nitrogen: acid rain and respiratory problems (f) sulfur dioxide: acid rain

·       State and explain strategies to reduce the effects of climate change: (a) planting trees (b) reduction in livestock farming, (c) decreasing use of fossil fuels (d) increasing use of renewable energy, e.g. wind, solar *

·       State strategies to reduce the effects of acid rain: reducing emissions of sulfur dioxide by using low-sulfur fuels *

·       Describe how the greenhouse gases carbon dioxide and methane cause global warming, limited to: (a) the absorption, reflection and emission of thermal energy (b) reducing thermal energy loss to space *

 

·       C11. Organic chemistry

11.1 Terminology

·       State that a saturated compound has molecules in which all carbon–carbon bonds are single bond

·       State that an unsaturated compound has molecules in which one or more carbon–carbon bonds are not single bonds

·       State that a homologous series is a family of similar compounds with similar chemical properties *

·       Describe the general characteristics of a homologous series as: (a) having the same general formula (recall of specific general formulas is not required) (b) displaying a trend in physical properties *

 

11.2 Fuels

·       Name the fossil fuels: coal, natural gas and petroleum

·       Name methane as the main constituent of natural gas

·       State that hydrocarbons are compounds that contain hydrogen and carbon only

·       State that petroleum is a mixture of hydrocarbons

·       Describe the separation of petroleum into useful fractions by fractional distillation

·       Name the uses of the fractions as: (a) refinery gas fraction for gas used in heating and cooking (b) gasoline/petrol fraction for fuel used in cars (c) naphtha fraction as a chemical feedstock (d) diesel oil/gas oil for fuel used in diesel engines (e) bitumen for making roads

·       Describe how the properties of fractions obtained from petroleum change from the bottom to the top of the fractionating column, limited to: (a) decreasing chain length (b) lower boiling points *

 

11.3 Alkanes

·       State that the bonding in alkanes is single covalent and that alkanes are saturated hydrocarbons

·       Describe the properties of alkanes as being generally unreactive, except in terms of combustion

 

11.4 Alkenes

·       State that the bonding in alkenes includes a double carbon–carbon covalent bond and that alkenes are unsaturated hydrocarbons

·       Describe the test to distinguish between saturated and unsaturated hydrocarbons by their reaction with aqueous bromine

·       Describe the manufacture of alkenes and hydrogen by the cracking of larger alkane molecules using a high temperature and a catalyst

·       Describe the properties of alkenes in terms of addition reactions with: (a) bromine (b) hydrogen in the presence of a nickel catalyst (c) steam in the presence of an acid catalyst

 

11.5 Polymers

·       Define polymers as large molecules built up from many smaller molecules called monomers

·       State that the formation of poly(ethene) is an example of addition polymerisation using ethene (an alkene) monomers

 

 

·       C12. Experimental techniques and chemical analysis

 

12.1 Experimental design

·       1 Name appropriate apparatus for the measurement of time, temperature, mass and volume, including: (a) stop-watches (b) thermometers (c) balances (d) burettes (e) volumetric pipettes (f) measuring cylinders (g) gas syringes

·       Describe a: (a) solvent as a substance that dissolves a solute (b) solute as a substance that is dissolved in a solvent (c) solution as a mixture of one or more solutes dissolved in a solvent (d) saturated solution as a solution containing the maximum concentration of a solute dissolved in the solvent at a specified temperature (e) residue as a solid substance that remains after evaporation, distillation, filtration or any similar process (f) filtrate as a liquid or solution that has passed through a filter

 

12.2 Chromatography

·       Describe how paper chromatography is used to separate mixtures of soluble coloured substances, using a suitable solvent

·       Interpret simple chromatograms to identify: (a) unknown substances by comparison with known substances (b) pure and impure substances

·       State and use the equation for Rf : Rf = distance travelled by substance / distance travelled by solvent *

 

12.3 Separation and purification

·       Describe and explain methods of separation and purification using: (a) a suitable solvent (b) filtration (c) crystallisation (d) simple distillation (e) fractional distillation

·       Suggest suitable separation and purification techniques, given information about the substances involved

 

12.4 Identification of ions and gases

·       Describe tests to identify the anions:

(a) carbonate, CO3 2–, by reaction with dilute acid and then testing for carbon dioxide gas

(b) chloride, Cl –, bromide, Br – , and iodide, I – , by acidifying with dilute nitric acid then adding aqueous silver nitrate

(c) sulfate, SO4 2–, by acidifying with dilute nitric acid and then adding aqueous barium nitrate

·       Describe tests using aqueous sodium hydroxide and aqueous ammonia to identify the aqueous cations:

·       (a) ammonium, NH4 +

·       (b) calcium, Ca2+

·       (c) copper(II), Cu2+

·       (d) iron(II), Fe2+

·       (e) iron(III), Fe3+

·       (f) zinc, Zn2+ (formulas of complex ions are not required)

·       Describe tests to identify the gases:

·       (a) ammonia, NH3, using damp red litmus paper

·       (b) carbon dioxide, CO2, using limewater

·       (c) chlorine, Cl 2, using damp litmus paper (

·       d) hydrogen, H2, using a lighted splint

·       (e) oxygen, O2, using a glowing splint

·       Describe the use of a flame test to identify the cations:

·       (a) lithium, Li+

·       (b) sodium, Na+

·       (c) potassium, K+

·       (d) copper(II), Cu2+