Science 0654 (2025-): Chemistry

States of matter

Atoms, elements and compounds

Stoichiometry

Electrochemistry

Chemical energetics

Chemical reactions

Acids, bases and salts

The Periodic Table

Metals

Chemistry of the environment

Organic chemistry

Experimental techniques and chemical analysis

Solids, liquids and gases

Diffusion

Elements, compounds and mixtures

Atomic structure and the Periodic Table

Isotopes

lons and ionic bonds

Simple molecules and covalent bonds

Giant covalent structure

Metallic bonding

Formulas

Relative masses of atoms and molecules

The mole and the Avogadro constant

Electrolysis

Hydrogen-oxygen fuel cells

Exothermic and endothermic reactions

Physical and chemical changes

Rate of reaction

Redox

The characteristic properties of acids and bases

Oxides

Preparation of salts

Arrangement of elements

Group I properties

Group VII properties

Transition elements

Noble gases

Properties of metals

Uses of metals

Alloys and their properties

Reactivity series

Corrosion of metals

Extraction of metals

Water

Air quality and climate

Formulas and terminology

Naming organic compounds

Fuels

Alkanes

Alkenes

Alcohols

Polymers

Experimental design

Acid-base titrations

Chromatography

Separation and purification

Identification of ions and gases

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 changes of state in terms of melting, boiling, evaporating, freezing and condensing

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

Explain changes of state in terms of kinetic particle theory, including the interpretation of heating and cooling curves

Explain, in terms of kinetic particle theory, the effects of temperature and pressure on the volume of a gas

Describe and explain diffusion in terms of kinetic particle theory

Describe and explain the effect of relative molecular mass on the rate of diffusion of gases

Describe the differences between elements, compounds and mixtures

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, a neutron and an electron

Define proton number / atomic number as the 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, e.g. 2,8,3

State that:

Define isotopes as different atoms of the same element that have the same number of protons but different numbers of neutrons

Interpret and use symbols for atoms, e.g. (symbol for, including atomic number and mass) Carbon, and ions, e.g. Chloride ion

State that isotopes of the same element have the same chemical properties because they have the same number of electrons and therefore the same electronic configuration

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 VIll, including the use of dot-and-cross diagrams

Describe the properties of ionic compounds: 

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

Explain in terms of structure and bonding the properties of ionic compounds:

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

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, Cl2, H2O, CH4, NH3 and HCl. Use dot-and cross diagrams to show the electronic configurations in these molecules

Describe in terms of structure and bonding the properties of simple molecular compounds:

Describe the formation of covalent bonds in simple molecules, including СН3ОН, С2H4, O2, CO2, and Na. Use dot-and-cross diagrams to show the electronic configurations in these molecules

Explain in terms of structure and bonding the properties of simple molecular compounds:

Describe the giant covalent structures of graphite and diamond

Relate the structures and bonding of graphite and diamond to their uses, limited to:

Describe metallic bonding as the electrostatic attraction between the positive ions in a giant metallic lattice and a 'sea' of delocalised electrons

Explain in terms of structure and bonding the properties of metals:

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

Construct word equations to show how reactants form products

Balance and interpret simple symbol equations, including state symbols

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 symbol equations with state symbols, including ionic equations

Deduce the symbol equation with state symbols for a chemical reaction, given relevant information

Describe relative atomic mass, Ar, as the average mass of the isotopes of an element compared to 1/12th of the mass of an atom of Carbon-12

Define relative molecular mass, Mr, as the sum of the relative atomic masses. Relative formula mass, Mr will be used for ionic compounds

Calculate reacting masses in simple proportions (calculations will not involve the mole concept)

State that concentration can be measured in g/dm3

State that the mole, mol, is the unit of amount of substance and that one mole contains 6.02 × 10^23 particles, e.g. atoms, ions, molecules; this number is the Avogadro constant

se the relationship - Amount of substance (mol) = mass (g) / molar mass (g/mol) to calculate:

Use the molar gas volume, taken as 24 dm3 at room temperature and pressure, r.t.p., in calculations involving gases

Calculate stoichiometric reacting masses, limiting reactants, volumes of gases at r.t.p., including conversion between cm3 and dm3

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:

Identify the products formed at the electrodes and describe the observations made during the electrolysis of:

Describe the transfer of charge during electrolysis:

Identify the products formed at the electrodes and describe the observations made during the electrolysis of aqueous copper(II) sulfate using carbon/ graphite electrodes and when using copper electrodes

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

Construct ionic half-equations for reactions at the cathode (showing gain of electrons as a reduction reaction)

State that a hydrogen-oxygen fuel cell uses hydrogen and oxygen to produce electricity with water as the only chemical product

Describe the advantages and disadvantages of using hydrogen-oxygen fuel cells in comparison with gasoline/ petrol engines in vehicles

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

State that the transfer of thermal energy during a reaction is called the enthalpy change, ∆H, of the reaction. ∆H is negative for exothermic reactions and positive for 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:

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

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

Describe the effect on the rate of reaction of:

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

Explain the effect on the rate of reaction of: 

State that a catalyst decreases the activation energy, Ea, of a reaction

Describe collision theory in terms of:

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

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

Define oxidation in terms of:

Define reduction in terms of:

Describe the characteristic properties of acids in terms of their reactions with:

Describe acids in terms of their effect on the indicators:

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:

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

Describe the neutralisation reaction between an acid and an alkali to produce a salt and water (the ionic equation for this reaction is not required)

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

Describe amphoteric oxides as oxides that react with acids and with bases to produce a salt and water

Classify Al2O3 and ZnO as amphoteric oxides

Describe the preparation, separation and purification of soluble salts by reaction of an acid with:

Define a hydrated substance as a substance that is chemically combined with water and an anhydrous substance as a substance containing no water

Describe the preparation of insoluble salts by precipitation (the general solubility rules for salts are not required)

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

Explain similarities in the chemical properties of elements in the same group of the Periodic Table in terms of their electronic configuration

Identity trends in groups, given information about the elements

Describe the Group I alkali metals, lithium, sodium and potassium, as relatively soft metals with general trends down the group, limited to:

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

Describe the Group VII halogens, chlorine, bromine and iodine, as diatomic non-metals with general trends down the group, limited to:

State the appearance of the halogens at room temperature and pressure, r.t.p., as:

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

Describe the transition elements as metals that:

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

Compare the general physical properties of metals and non-metals, including:

Describe the general chemical properties of metals, limited to their reactions with:

Describe the uses of metals in terms of their physical properties, including:

Describe alloys as mixtures of a metal with other elements, including:

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

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:

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

Describe the relative reactivities of metals in terms of their tendency to form positive ions, by displacement reactions, if any, with the aqueous ions of magnesium, zinc, iron, copper and silver

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

Describe the use of zinc in galvanising steel as an example of a barrier method and sacrificial protection

Explain sacrificial protection in terms of the reactivity series and in terms of electron loss

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(IIl) 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:

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

Describe how to test for the purity of water using melting point and boiling point

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:

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:

State the adverse effect of these air pollutants, limited to:

State and explain strategies to reduce the effects of climate change:

State and explain strategies to reduce the effects of acid rain: reducing emissions of sulfur dioxide by using low-sulfur fuels and flue gas desulfurisation with calcium oxide

Describe how the greenhouse gases carbon dioxide and methane cause global warming, limited to:

Explain how oxides of nitrogen form in car engines and describe their removal by catalytic converters, limited to: 2CO + 2NO → 2CO2 + N2

Draw and interpret the displayed formula of a molecule to show all the atoms and all the bonds

State that a saturated compound has molecules in which all carbon-carbon bonds are single bonds

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:

Name and draw the displayed formulas of: 

State the type of compound present, given a chemical name ending in -ane, -ene or -ol, or from a molecular formula or displayed formula

Name and draw the structural formulas and displayed formulas of unbranched: 

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:

Describe how the properties of fractions obtained from petroleum change from the bottom to the top of the fractionating column, limited to:

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

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:

Describe the complete combustion of ethanol

State the uses of ethanol as: 

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

Describe the formation of poly(ethene) as an example of addition polymerisation using ethene monomers

Identify the repeat units in addition polymers and in condensation polymers

Deduce the structure or repeat unit of an addition polymer from a given alkene and vice versa

Describe the differences between addition and condensation polymerisation

Describe and draw the structure of nylon, a polyamide

Name appropriate apparatus for the measurement of time, temperature, mass and volume, including:

Describe a:

Describe an acid-base titration to include the use of a: 

Describe how to identify the end-point of a titration using an indicator

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

Interpret simple chromatograms to identify: 

State and use the equation for Rf: Rf = Distance travelled by the substance / Distance travelled by solvent

Describe and explain methods of separation and purification using:

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

Identify substances and assess their purity from melting point and boiling point information

Describe tests to identify the anions:

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

Describe tests to identify the gases:

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

Group Vill noble gases have a full outer shell

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

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

high melting points and boiling points 

good electrical conductivity when aqueous or molten and poor when solid

generally soluble in water

high melting points and boiling points

good electrical conductivity when aqueous or molten and poor when solid

low melting points and boiling points 

poor electrical conductivity

low melting points and boiling points in terms of weak intermolecular forces (specific types of intermolecular forces are not required) 

poor electrical conductivity

graphite as a lubricant and as an electrode

diamond in cutting tools

good electrical conductivity

malleability

amount of substance (b) mass 

molar mass

relative atomic mass or relative molecular/ formula mass

the anode as the positive electrode

the cathode as the negative electrode 

the electrolyte as the molten or aqueous substance that undergoes electrolysis

molten lead(II) bromide

concentrated aqueous sodium chloride

dilute sulfuric acid using inert electrodes made of platinum or carbon/ graphite

the movement of electrons in the external circuit

the loss or gain of electrons at the electrodes

the movement of ions in the electrolyte

reactants

products

overall energy change of the reaction, ∆H (d) activation energy, Ea

changing the concentration of solutions

changing the pressure of gases 

changing the surface area of solids 

changing the temperature

adding or removing a catalyst

changing the concentration of solutions

changing the pressure of gases 

changing the surface area of solids 

changing the temperature 

adding or removing a catalyst using collision theory 

number of particles per unit volume

frequency of collisions between particles

kinetic energy of particles 

activation energy, Ea

loss of electrons

an increase in oxidation number (determination of oxidation numbers is not required)

gain of electrons

a decrease in oxidation number (determination of oxidation numbers is not required)

metals

bases

carbonates

litmus

methyl orange

litmus

methyl orange

an alkali by titration

excess metal

excess insoluble base

excess insoluble carbonate (the general solubility rules for salts are not required)

decreasing melting point 

increasing density 

increasing reactivity with water

increasing density 

decreasing reactivity

chlorine, a pale yellow-green gas 

bromine, a red-brown liquid 

iodine, a grey-black solid

have high densities 

have high melting points

form coloured compounds

often act as catalysts as elements and in compounds

thermal conductivity 

electrical conductivity

malleability and ductility 

melting points and boiling points

dilute acids

cold water and steam

aluminium in the manufacture of aircraft because of its low density

aluminium in the manufacture of overhead electrical cables because of its low density and good electrical conductivity 

aluminium in food containers because of its resistance to corrosion

copper in electrical wiring because of its good electrical conductivity

brass as a mixture of copper and zinc 

stainless steel as a mixture of iron and other elements such as chromium, nickel and carbon

potassium, sodium and calcium with cold water

magnesium with steam 

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

the burning of carbon (coke) to provide heat and produce carbon dioxide C + O2 → CO2

the reduction of carbon dioxide to carbon monoxide С + СО2 → 2CO

the reduction of iron(III) oxide by carbon monoxide Fe2O3 + 3CO → 2Fe + 3CO2

the thermal decomposition of calcium carbonate/ limestone to produce calcium oxide CaCO3 → CaO + CO2

the formation of slag CaO + SiO2 → CaSiO3

sedimentation and filtration to remove solids

use of carbon to remove tastes and odours

chlorination to kill microbes (pathogens)

carbon dioxide from the complete combustion of carbon-containing fuels 

carbon monoxide and particulates from the incomplete combustion of carbon containing fuels 

methane from the decomposition of vegetation and waste gases from digestion in animals (d) oxides of nitrogen from car engines

sulfur dioxide from the combustion of fossil fuels which contain sulfur compounds

carbon dioxide: higher levels of carbon dioxide leading to increased global warming, which leads to climate change 

carbon monoxide: toxic gas

particulates: increased risk of respiratory problems and cancer 

methane: higher levels of methane leading to increased global warming, which leads to climate change

oxides of nitrogen: acid rain and respiratory problems 

sulfur dioxide: acid rain

planting trees 

reduction in livestock farming 

decreasing use of fossil fuels 

increasing use of hydrogen and renewable energy, e.g. wind, solar

the absorption, reflection and emission of thermal energy 

reducing thermal energy loss to space

having the same general formula (recall of specific general formulas is not required) 

displaying a trend in physical properties

methane and ethane 

ethene

ethanol

alkanes

alkenes, including but-1-ene and but-2-ene (not cis/trans) containing up to four carbon atoms per molecule

refinery gas fraction for gas used in heating and cooking 

gasoline / petrol fraction for fuel used in cars

naphtha fraction as a chemical feedstock 

diesel oil / gas oil for fuel used in diesel engines 

bitumen for making roads

decreasing chain length 

lower boiling points

bromine

hydrogen in the presence of a nickel catalyst 

steam in the presence of an acid catalyst

a solvent

a fuel

stop-watches

thermometers

balances

burettes

volumetric pipettes 

measuring cylinders

gas syringes

solvent as a substance that dissolves a solute

solute as a substance that is dissolved in a solvent

solution as a mixture of one or more solutes dissolved in a solvent

saturated solution as a solution containing the maximum concentration of a solute dissolved in the solvent at a specified temperature

residue as a solid substance that remains after evaporation, distillation, filtration or any similar process

filtrate as a liquid or solution that has passed through a filter

burette

volumetric pipette 

suitable indicator

unknown substances by comparison with known substances

pure and impure substances

a suitable solvent

filtration

crystallisation

simple distillation

fractional distillation

carbonate, CO3²⁻ by reaction with dilute acid and then testing for carbon dioxide gas

chloride, C⁻, bromide, Br⁻, and iodide, I⁻, by acidifying with dilute nitric acid then adding aqueous silver nitrate

nitrate, NO3⁻ , reduction with aluminium foil and aqueous sodium hydroxide and then testing for ammonia gas

sulfate, SO4²⁻ by acidifying with dilute nitric acid and then adding aqueous barium nitrate

ammonium, NH4⁺

calcium, Ca²⁺

copper(II), Cu²⁺

iron(LI), Fe²⁺

iron(III), Fe³⁺

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

ammonia, NH3, using damp red litmus paper

carbon dioxide, CO2, using limewater 

chlorine, Cl2, using damp litmus paper 

hydrogen, H2, using a lighted splint 

oxygen, O2, using a glowing splint

lithium, Li⁺

sodium, Na⁺

potassium, K⁺ 

copper(II), Cu²⁺