GCSE Chemistry

Formulae, equations and hazards

Topic 1 – Key concepts in chemistry

Topic 2 – States of matter and mixtures

Topic 3 – Chemical changes

Topic 4 – Extracting metals and equilibria

Topic 5 – Separate chemistry 1

Topic 6 – Groups in the periodic table

Topic 7 – Rates of reaction and energy changes

Topic 8 – Fuels and Earth science 

Topic 9 – Separate chemistry 2

Recall the formulae of elements, simple compounds and ions

Write word equations

Write balanced chemical equations, including the use of the state symbols (s), (l), (g) and (aq)

Write balanced ionic equations [H]

Describe the use of hazard symbols on containers

Evaluate the risks in a practical procedure and suggest suitable precautions for a range of practicals including those mentioned in the specification

Describe how the Dalton model of an atom has changed over time because of the discovery of subatomic particles

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

Recall the relative charge and relative mass of:

Explain why atoms contain equal numbers of protons and electrons

Describe the nucleus of an atom as very small compared to the overall size of the atom

Recall that most of the mass of an atom is concentrated in the nucleus

Recall the meaning of the term mass number of an atom

Describe atoms of a given element as having the same number of protons in the nucleus and that this number is unique to that element

Describe isotopes as different atoms of the same element containing the same number of protons but different numbers of neutrons in their nuclei

Calculate the numbers of protons, neutrons and electrons in atoms given the atomic number and mass number

Explain how the existence of isotopes results in relative atomic masses of some elements not being whole numbers

Calculate the relative atomic mass of an element from the relative masses and abundances of its isotopes [H]

Describe how Mendeleev arranged the elements, known at that time, in a periodic table by using properties of these elements and their compounds

Describe how Mendeleev used his table to predict the existence and properties of some elements not then discovered

Explain that Mendeleev thought he had arranged elements in order of increasing relative atomic mass but this was not always true because of the relative abundance of isotopes of some pairs of elements in the periodic table

Explain the meaning of atomic number of an element in terms of position in the periodic table and number of protons in the nucleus

Describe that in the periodic table

Identify elements as metals or non-metals according to their position in the periodic table, explaining this division in terms of the atomic structures of the elements

Predict the electronic configurations of the first 20 elements in the periodic table as diagrams and in the form, for example 2.8.1

Explain how the electronic configuration of an element is related to its position in the periodic table

Explain how ionic bonds are formed by the transfer of electrons between atoms to produce cations and anions, including the use of dot and cross diagrams

Recall that an ion is an atom or group of atoms with a positive or negative charge

Calculate the numbers of protons, neutrons and electrons in simple ions given the atomic number and mass number

Explain the formation of ions in ionic compounds from their atoms, limited to compounds of elements in groups 1, 2, 6 and 7

Explain the use of the endings –ide and –ate in the names of compounds

Deduce the formulae of ionic compounds (including oxides, hydroxides, halides, nitrates, carbonates and sulfates) given the formulae of the constituent ions

Explain the structure of an ionic compound as a lattice structure

Explain how a covalent bond is formed when a pair of electrons is shared between two atoms

Recall that covalent bonding results in the formation of molecules

Recall the typical size (order of magnitude) of atoms and small molecules

Explain the formation of simple molecular, covalent substances, using dot and cross diagrams, including:

Explain how the structure and bonding of these types of substances results in different physical properties, including relative melting point and boiling point, relative solubility in water and ability to conduct electricity (as solids and in solution) AND why elements and compounds can be classed as:

Explain the properties of ionic compounds limited to:

Explain the properties of typical covalent, simple molecular compounds limited to:

Recall that graphite and diamond are different forms of carbon and that they are examples of giant covalent substances

Describe the structures of graphite and diamond

Explain, in terms of structure and bonding, why graphite is used to make electrodes and as a lubricant, whereas diamond is used in cutting tools

Explain the properties of fullerenes including C60 and graphene in terms of their structures and bonding

Describe, using poly(ethene) as the example, that simple polymers consist of large molecules containing chains of carbon atoms

Explain the properties of metals, including malleability and the ability to conduct electricity

Describe the limitations of particular representations and models, to include dot and cross, ball and stick models and two- and three-dimensional representations

Describe most metals as shiny solids which have high melting points, high density and are good conductors of electricity whereas most non-metals have low boiling points and are poor conductors of electricity

Calculate relative formula mass given relative atomic masses

Calculate the formulae of simple compounds from reacting masses or percentage composition and understand that these are empirical formulae

Deduce:

Describe an experiment to determine the empirical formula of a simple compound such as magnesium oxide 

Explain the law of conservation of mass applied to:

Calculate masses of reactants and products from balanced equations, given the mass of one substance

Calculate the concentration of solutions in g dm–3

Recall that one mole of particles of a substance is defined as:

Calculate the number of:

Explain why, in a reaction, the mass of product formed is controlled by the mass of the reactant which is not in excess

Deduce the stoichiometry of a reaction from the masses of the reactants and products

Describe the arrangement, movement and the relative energy of particles in each of the three states of matter: solid, liquid and gas

Recall the names used for the interconversions between the three states of matter, recognising that these are physical changes: contrasted with chemical reactions that result in chemical changes

Explain the changes in arrangement, movement and energy of particles during these interconversions

Predict the physical state of a substance under specified conditions, given suitable data

Explain the difference between the use of ‘pure’ in chemistry compared with its everyday use and the differences in chemistry between a pure substance and a mixture

Interpret melting point data to distinguish between pure substances which have a sharp melting point and mixtures which melt over a range of temperatures

Explain the types of mixtures that can be separated by using the following experimental techniques:

Describe an appropriate experimental technique to separate a mixture, knowing the properties of the components of the mixture

Describe paper chromatography as the separation of mixtures of soluble substances by running a solvent (mobile phase) through the mixture on the paper (the paper contains the stationary phase), which causes the substances to move at different rates over the paper

Interpret a paper chromatogram:

Core Practical: Investigate the composition of inks using simple distillation and paper chromatography

Describe how:

Recall that acids in solution are sources of hydrogen ions and alkalis in solution are sources of hydroxide ions

Recall that a neutral solution has a pH of 7 and that acidic solutions have lower pH values and alkaline solutions higher pH values

Recall the effect of acids and alkalis on indicators, including litmus, methyl orange and phenolphthalein

Recall that the higher the concentration of hydrogen ions in an acidic solution, the lower the pH; and the higher the concentration of hydroxide ions in an alkaline solution, the higher the pH [H]

Recall that as hydrogen ion concentration in a solution increases by a factor of 10, the pH of the solution decreases by 1 [H]

Core Practical: Investigate the change in pH on adding powdered calcium hydroxide or calcium oxide to a fixed volume of dilute hydrochloric acid

Explain the terms dilute and concentrated, with respect to amount of substances in solution [H]

Explain the terms weak and strong acids, with respect to the degree of dissociation into ions [H]

Recall that a base is any substance that reacts with an acid to form a salt and water only

Recall that alkalis are soluble bases

Explain the general reactions of aqueous solutions of acids with the following to produce salts:

Describe the chemical test for:

Describe a neutralisation reaction as a reaction between an acid and a base

Explain an acid-alkali neutralisation as a reaction in which hydrogen ions (H+) from the acid react with hydroxide ions (OH–) from the alkali to form water

Explain why, if soluble salts are prepared from an acid and an insoluble reactant:

Explain why, if soluble salts are prepared from an acid and a soluble reactant:

Core Practical: Investigate the preparation of pure, dry hydrated copper sulfate crystals starting from copper oxide including the use of a water bath

Describe how to carry out an acid-alkali titration, using burette, pipette and a suitable indicator, to prepare a pure, dry salt

Recall the general rules which describe the solubility of common types of substances in water: 

Predict, using solubility rules, whether or not a precipitate will be formed when named solutions are mixed together, naming the precipitate if any

Describe the method used to prepare a pure, dry sample of an insoluble salt

Recall that electrolytes are ionic compounds in the molten state or dissolved in water

Describe electrolysis as a process in which electrical energy, from a direct current supply, decomposes electrolytes

Explain the movement of ions during electrolysis, in which:

Explain the formation of the products in the electrolysis, using inert electrodes, of some electrolytes, including:

Predict the products of electrolysis of other binary, ionic compounds in the molten state

Write half equations for reactions occurring at the anode and cathode in electrolysis [H]

Explain oxidation and reduction in terms of loss or gain of electrons [H]

Recall that reduction occurs at the cathode and that oxidation occurs at the anode in electrolysis reactions [H]

Explain the formation of the products in the electrolysis of copper sulfate solution, using copper electrodes, and how this electrolysis can be used to purify copper

Core Practical: Investigate the electrolysis of copper sulfate solution with inert electrodes and copper electrodes

Deduce the relative reactivity of some metals, by their reactions with water, acids and salt solutions

Explain displacement reactions as redox reactions, in terms of gain or loss of electrons [H]

Explain the reactivity series of metals (potassium, sodium, calcium, magnesium, aluminium, (carbon), zinc, iron, (hydrogen), copper, silver, gold) in terms of the reactivity of the metals with water and dilute acids and that these reactions show the relative tendency of metal atoms to form cations

Recall that:

Explain oxidation as the gain of oxygen and reduction as the loss of oxygen

Recall that the extraction of metals involves reduction of ores

Explain why the method used to extract a metal from its ore is related to its position in the reactivity series and the cost of the extraction process, illustrated by: (knowledge of blast furnace is not required)

Evaluate alternative biological methods of metal extraction (bacterial and phytoextraction) [H]

Explain how a metal’s relative resistance to oxidation is related to its position in the reactivity series

Evaluate the advantages of recycling metals, including economic implications and how recycling can preserve both the environment and the supply of valuable raw materials

Describe that a life-cycle assessment for a product involves consideration of the effect on the environment of obtaining the raw materials, manufacturing the product, using the product and disposing of the product when it is no longer useful 

Evaluate data from a life cycle assessment of a product

Recall that chemical reactions are reversible, the use of the symbol ⇌ in equations and that the direction of some reversible reactions can be altered by changing the reaction conditions

Explain what is meant by dynamic equilibrium

Describe the formation of ammonia as a reversible reaction between nitrogen (extracted from the air) and hydrogen (obtained from natural gas) and that it can reach a dynamic equilibrium

Recall the conditions for the Haber process as:

Predict how the position of a dynamic equilibrium is affected by changes in: [H]

Recall that most metals are transition metals and that their typical properties (as exemplified by iron) include:

Recall that the oxidation of metals results in corrosion

Explain how rusting of iron can be prevented by: 

Explain how electroplating can be used to improve the appearance and/or the resistance to corrosion of metal objects

Explain, using models, why converting pure metals into alloys often increases the strength of the product

Explain why iron is alloyed with other metals to produce alloy steels

Explain how the uses of metals are related to their properties (and vice versa), including aluminium, copper and gold and their alloys including magnalium and brass 

Calculate the concentration of solutions in mol dm–3 and convert concentration in g dm–3 into mol dm–3 and vice versa [H]

Core Practical: Carry out an accurate acid-alkali titration, using burette, pipette and a suitable indicator 

Carry out simple calculations using the results of titrations to calculate an unknown concentration of a solution or an unknown volume of solution required [H]

Calculate the percentage yield of a reaction from the actual yield and the theoretical yield 

Describe that the actual yield of a reaction is usually less than the theoretical yield and that the causes of this include: 

Recall the atom economy of a reaction forming a desired product

Calculate the atom economy of a reaction forming a desired product

Explain why a particular reaction pathway is chosen to produce a specified product, given appropriate data such as atom economy, yield, rate, equilibrium position and usefulness of by-products [H]

Describe the molar volume, of any gas at room temperature and pressure, as the volume occupied by one mole of molecules of any gas at room temperature and pressure (The molar volume will be provided as 24 dm3 or 24000 cm3 in calculations where it is required) [H]

Use the molar volume and balanced equations in calculations involving the masses of solids and volumes of gases [H]

Use Avogadro’s law to calculate volumes of gases involved in a gaseous reaction, given the relevant equation [H]

Describe the Haber process as a reversible reaction between nitrogen and hydrogen to form ammonia

Predict how the rate of attainment of equilibrium is affected by: [H]

Explain how, in industrial reactions, including the Haber process, conditions used are related to: [H]

Recall that fertilisers may contain nitrogen, phosphorus and potassium compounds to promote plant growth

Describe how ammonia reacts with nitric acid to produce a salt that is used as a fertiliser 

Describe and compare:

Recall that a chemical cell produces a voltage until one of the reactants is used up

Recall that in a hydrogen–oxygen fuel cell hydrogen and oxygen are used to produce a voltage and water is the only product

Evaluate the strengths and weaknesses of fuel cells for given uses

Explain why some elements can be classified as alkali metals (group 1), halogens (group 7) or noble gases (group 0), based on their position in the periodic table 

Recall that alkali metals:

Describe the reactions of lithium, sodium and potassium with water

Describe the pattern in reactivity of the alkali metals, lithium, sodium and potassium, with water; and use this pattern to predict the reactivity of other alkali metals

Explain this pattern in reactivity in terms of electronic configurations

Recall the colours and physical states of chlorine, bromine and iodine at room temperature

Describe the pattern in the physical properties of the halogens, chlorine, bromine and iodine, and use this pattern to predict the physical properties of other halogens

Describe the chemical test for chlorine

Describe the reactions of the halogens, chlorine, bromine and iodine, with metals to form metal halides, and use this pattern to predict the reactions of other halogens 

Recall that the halogens, chlorine, bromine and iodine, form hydrogen halides which dissolve in water to form acidic solutions, and use this pattern to predict the reactions of other halogens

Describe the relative reactivity of the halogens chlorine, bromine and iodine, as shown by their displacement reactions with halide ions in aqueous solution, and use this pattern to predict the reactions of astatine 

Explain why these displacement reactions are redox reactions in terms of gain and loss of electrons, identifying which of the substances are oxidised and which are reduced [H]

Explain the relative reactivity of the halogens in terms of electronic configurations

Explain why the noble gases are chemically inert, compared with the other elements, in terms of their electronic configurations

Explain how the uses of noble gases depend on their inertness, low density and/or non-flammability

Describe the pattern in the physical properties of some noble gases and use this pattern to predict the physical properties of other noble gases

Core Practical: Investigate the effects of changing the conditions of a reaction on the rates of chemical reactions by:

Suggest practical methods for determining the rate of a given reaction

Explain how reactions occur when particles collide and that rates of reaction are increased when the frequency and/or energy of collisions is increased 

Explain the effects on rates of reaction of changes in temperature, concentration, surface area to volume ratio of a solid and pressure (on reactions involving gases) in terms of frequency and/or energy of collisions between particles

Interpret graphs of mass, volume or concentration of reactant or product against time

Describe a catalyst as a substance that speeds up the rate of a reaction without altering the products of the reaction, being itself unchanged chemically and in mass at the end of the reaction

Explain how the addition of a catalyst increases the rate of a reaction in terms of activation energy

Recall that enzymes are biological catalysts and that enzymes are used in the production of alcoholic drinks

Recall that changes in heat energy accompany the following changes (and that, when these reactions take place in solution, temperature changes can be measured to reflect the heat changes):

Describe an exothermic change or reaction as one in which heat energy is given out

Describe an endothermic change or reaction as one in which heat energy is taken in

Recall that the breaking of bonds is endothermic and the making of bonds is exothermic

Recall that the overall heat energy change for a reaction is:

Calculate the energy change in a reaction given the energies of bonds (in kJ mol–1) [H]

Explain the term activation energy

Draw and label reaction profiles for endothermic and exothermic reactions, identifying activation energy

Recall that hydrocarbons are compounds that contain carbon and hydrogen only

Describe crude oil as:

Describe and explain the separation of crude oil into simpler, more useful mixtures by the process of fractional distillation

Recall the names and uses of the following fractions: 

Explain how hydrocarbons in different fractions are mostly members of the alkane homologous series, and differ from each other in:

Explain an homologous series as a series of compounds which:

Describe the complete combustion of hydrocarbon fuels as a reaction in which:

Explain why the incomplete combustion of hydrocarbons can produce carbon and carbon monoxide

Explain how carbon monoxide behaves as a toxic gas

Describe the problems caused by incomplete combustion producing carbon monoxide and soot in appliances that use carbon compounds as fuels

Explain how impurities in some hydrocarbon fuels result in the production of sulfur dioxide

Explain some problems associated with acid rain caused when sulfur dioxide dissolves in rain water

Explain why, when fuels are burned in engines, oxygen and nitrogen can react together at high temperatures to produce oxides of nitrogen, which are pollutants

Evaluate the advantages and disadvantages of using hydrogen, rather than petrol, as a fuel in cars

Recall that petrol, kerosene and diesel oil are non-renewable fossil fuels obtained from crude oil and methane is a nonrenewable fossil fuel found in natural gas

Explain how cracking involves the breaking down of larger, saturated hydrocarbon molecules (alkanes) into smaller, more useful ones, some of which are unsaturated (alkenes)

Explain why cracking is necessary

Recall that the gases produced by volcanic activity formed the Earth’s early atmosphere

Describe (and interpret evidence relating to) that the Earth’s early atmosphere was thought to contain:

Explain how condensation of water vapour formed oceans

Explain how the amount of carbon dioxide in the atmosphere was decreased when carbon dioxide dissolved as the oceans formed

Explain how the growth of primitive plants used carbon dioxide and released oxygen by photosynthesis and consequently the amount of oxygen in the atmosphere gradually increased 

Describe the chemical test for oxygen

Describe how various gases in the atmosphere, including carbon dioxide, methane and water vapour, absorb heat radiated from the Earth, subsequently releasing energy which keeps the Earth warm: this is known as the greenhouse effect

Evaluate the evidence for human activity causing climate change, considering: 

Describe:

Explain why the test for any ion must be unique

Describe flame tests to identify the following ions in solids:

Describe test, using sodium hydroxide solution, to identify the following ions in solids or solutions as appropriate:

Describe the chemical test for ammonia

Describe tests to identify the following ions in solids or solutions as appropriate: 

Core Practical: Identify the ions in unknown salts, using the tests for the specified cations and anions in 9.2C, 9.3C, 9.4C, 9.5C

Identify the ions in unknown salts, using results of the tests above

Describe that instrumental methods of analysis are available and that these may improve sensitivity, accuracy and speed of tests

Evaluate data from a flame photometer (no knowledge of the instrument or how it works is required): 

Recall the formulae of molecules of the alkanes, methane, ethane, propane and butane, and draw the structures of these molecules, showing all covalent bonds

Explain why the alkanes are saturated hydrocarbons

Recall the formulae of molecules of the alkenes, ethene, propene, butene, and draw the structures of these molecules, showing all covalent bonds (but-1-ene and but-2-ene only)

Explain why the alkenes are unsaturated hydrocarbons, describing that their molecules contain the functional group C=C

Recall the addition reaction of ethene with bromine, showing the structures of reactants and products, and extend this to other alkenes

Explain how bromine water is used to distinguish between alkanes and alkenes

Describe how the complete combustion of alkanes and alkenes involves the oxidation of the hydrocarbons to produce carbon dioxide and water

Recall that a polymer is a substance of high average relative molecular mass made up of small repeating units

Describe (conditions and mechanisms not required) :

Describe how other addition polymers can be made by combining together other monomer molecules containing C=C, to include poly(propene), poly(chloroethene) (PVC) and poly(tetrafluoroethene) (PTFE) (conditions and mechanisms not required)

Deduce the structure of a monomer from the structure of an addition polymer and vice versa

Explain how the uses of polymers are related to their properties and vice versa: including poly(ethene), poly(propene), poly(chloroethene) (PVC) and poly(tetrafluoroethene) (PTFE) 

Explain: [H]

Describe some problems associated with polymers including the:

Evaluate the advantages and disadvantages of recycling polymers, including economic implications, availability of starting materials and environmental impact

Recall that:

Recall the formulae of molecules of the alcohols, methanol, ethanol, propanol (propan-1-ol only) and butanol (butan-1-ol only), and draw the structures of these molecules, showing all covalent bonds

Recall that the functional group in alcohols is –OH and that alcohols can be dehydrated to form alkenes 

Core Practical: Investigate the temperature rise produced in a known mass of water by the combustion of the alcohols ethanol, propanol, butanol and pentanol

Recall the formulae of molecules of the carboxylic acids, methanoic, ethanoic, propanoic and butanoic acids, and draw the structures of these molecules, showing all covalent bonds

Recall that the functional group in carboxylic acids is –COOH and that solutions of carboxylic acids have typical acidic properties

Recall that ethanol can be oxidised to produce ethanoic acid and extend this to other alcohols (reagents not required)

Recall members of a given homologous series have similar reactions because their molecules contain the same functional group and use this to predict the products of other members of these series

Describe the production of ethanol by fermentation of carbohydrates in aqueous solution, using yeast to provide enzymes

Explain how to obtain a concentrated solution of ethanol by fractional distillation of the fermentation mixture

Compare the size of nanoparticles with the sizes of atoms and molecules

Describe how the properties of nanoparticulate materials are related to their uses including surface area to volume ratio of the particles they contain, including sunscreens

Explain the possible risks associated with some nanoparticulate materials

Compare, using data, the physical properties of glass and clay ceramics, polymers, composites and metals

Explain why the properties of a material make it suitable for a given use and use data to select materials appropriate for specific uses

to indicate the dangers associated with the contents

to inform people about safe-working precautions with these substances in the laboratory

a proton

a neutron

an electron

elements are arranged in order of increasing atomic number, in rows called periods

elements with similar properties are placed in the same vertical columns called groups 

consisting of a regular arrangement of ions

held together by strong electrostatic forces (ionic bonds) between oppositely-charged ions

hydrogen

hydrogen chloride

water

methane

oxygen

carbon dioxide

ionic

simple molecular (covalent)

giant covalent

metallic

high melting points and boiling points, in terms of forces between ions

whether or not they conduct electricity as solids, when molten and in aqueous solution

low melting points and boiling points, in terms of forces between molecules (intermolecular forces)

poor conduction of electricity

the empirical formula of a compound from the formula of its molecule

the molecular formula of a compound from its empirical formula and its relative molecular mass

a closed system including a precipitation reaction in a closed flask

a non-enclosed system including a reaction in an open flask that takes in or gives out a gas

the Avogadro constant number of particles (6.02 × 1023 atoms, molecules, formulae or ions) of that substance [H]

a mass of ‘relative particle mass’ g [H]

moles of particles of a substance in a given mass of that substance and vice versa [H]

particles of a substance in a given number of moles of that substance and vice versa [H]

particles of a substance in a given mass of that substance and vice versa [H]

simple distillation

fractional distillation

filtration

crystallisation

paper chromatagraphy

to distinguish between pure and impure substances

to identify substances by comparison with known substances

to identify substances by calculation and use of Rf values

waste and ground water can be made potable, including the need for sedimentation, filtration and chlorination 

sea water can be made potable by using distillation 

water used in analysis must not contain any dissolved salts

metals

metal oxides

metal hydroxides

metal carbonates

hydrogen

carbon dioxide (using limewater)

excess of the reactant is added

the excess reactant is removed

the solution remaining is only salt and water

titration must be used

the acid and the soluble reactant are then mixed in the correct proportions

the solution remaining, after reaction, is only salt and water

all common sodium, potassium and ammonium salts are soluble

all nitrates are soluble

common chlorides are soluble except those of silver and lead

common sulfates are soluble except those of lead, barium and calcium

common carbonates and hydroxides are insoluble except those of sodium, potassium and ammonium

positively charged cations migrate to the negatively charged cathode 

negatively charged anions migrate to the positively charged anode

copper chloride solution

sodium chloride solution

sodium sulfate solution

water acidified with sulfuric acid

molten lead bromide (demonstration)

most metals are extracted from ores found in the Earth’s crust

unreactive metals are found in the Earth’s crust as the uncombined elements

heating with carbon (including iron)

electrolysis (including aluminium)

temperature 450 °C

pressure 200 atmospheres

iron catalyst

temperature [H]

pressure [H]

concentration [H]

high melting point

high density

the formation of coloured compounds

catalytic activity of the metals and their compounds

exclusion of oxygen

exclusion of water

sacrificial protection 

incomplete reactions

practical losses during the experiment

competing, unwanted reactions (side reactions)

changes in temperature [H]

changes in pressure [H]

changes in concentration [H]

use of a catalyst [H]

the availability and cost of raw materials and energy supplies [H]

the control of temperature, pressure and catalyst used produce an acceptable yield in an acceptable time [H]

the laboratory preparation of ammonium sulfate from ammonia solution and dilute sulfuric acid on a small scale

the industrial production of ammonium sulfate, used as a fertiliser, in which several stages are required to produce ammonia and sulfuric acid from their raw materials and the production is carried out on a much larger scale (details of the industrial production of sulfuric acid are not required) 

are soft

have relatively low melting points

measuring the production of a gas (in the reaction between hydrochloric acid and marble chips)

observing a colour change (in the reaction between sodium thiosulfate and hydrochloric acid)

salts dissolving in water 

neutralisation reactions

displacement reactions

precipitation reactions

exothermic if more heat energy is released in forming bonds in the products than is required in breaking bonds in the reactants

endothermic if less heat energy is released in forming bonds in the products than is required in breaking bonds in the reactants

a complex mixture of hydrocarbons

containing molecules in which carbon atoms are in chains or rings (names, formulae and structures of specific ring molecules not required) 

an important source of useful substances (fuels and feedstock for the petrochemical industry) 

a finite resource

gases, used in domestic heating and cooking

petrol, used as fuel for cars

kerosene, used as fuel for aircraft

diesel oil, used as fuel for some cars and trains

fuel oil, used as fuel for large ships and in some power stations

bitumen, used to surface roads and roofs

the number of carbon and hydrogen atoms their molecules contain

boiling points

ease of ignition

viscosity

have the same general formula

differ by CH2 in molecular formulae from neighbouring compounds

show a gradual variation in physical properties, as exemplified by their boiling points

have similar chemical properties

carbon dioxide and water are produced

energy is given out

little or no oxygen

a large amount of carbon dioxide

water vapour

small amounts of other gases

the correlation between the change in atmospheric carbon dioxide concentration, the consumption of fossil fuels and temperature change

the uncertainties caused by the location where these measurements are taken and historical accuracy

the composition of today’s atmosphere

the potential effects on the climate of increased levels of carbon dioxide and methane generated by human activity, including burning fossil fuels and livestock farming

that these effects may be mitigated: consider scale, risk and environmental implications

lithium ion, Li+ (red)

sodium ion, Na+ (yellow)

potassium ion, K+ (lilac)

calcium ion, Ca2+ (orange-red)

copper ion, Cu2+ (blue-green)

aluminium ion, Al3+

calcium ion, Ca2+

copper ion, Cu2+

iron(II) ion, Fe2+

iron(III) ion, Fe3+

ammonium ion, NH4 +

carbonate ion, CO3 2–, using dilute acid and identifying the carbon dioxide evolved

sulfate ion, SO4 2–, using dilute hydrochloric acid and barium chloride solution

chloride ion, Cl–, bromide ion, Br–, iodide ion, I–, using dilute nitric acid and silver nitrate solution

to determine the concentration of ions in dilute solution using a calibration curve 

to identify metal ions by comparing the data with reference data

how ethene molecules can combine together in a polymerisation reaction 

that the addition polymer formed is called poly(ethene)

why polyesters are condensation polymers [H]

how a polyester is formed when a monomer molecule containing two carboxylic acid groups is reacted with a monomer molecule containing two alcohol groups [H]

how a molecule of water is formed each time an ester link is formed [H]

availability of starting materials

persistence in landfill sites, due to non-biodegradability

gases produced during disposal by combustion

requirement to sort polymers so that they can be melted and reformed into a new product

DNA is a polymer made from four different monomers called nucleotides (names of nucleotides not required)

starch is a polymer based on sugars

proteins are polymers based on amino acids