Students will gain a solid understanding of the key concepts that underpin all other topics in A-Level chemistry. Amount of substance relates to the skills required to calculate the amount of solids, liquids, gases and concentration of reactants or products in any reaction. Students also build on their understanding of atomic structure from GCSE chemistry which will then enable a deeper understanding of the bonding and structure of molecules and compounds.
Atoms of same element with different numbers of neutrons
Number of protons in the nucleus of an atom
Mass of an atom of an isotope compared with 1/12 the mass of an atom of carbon-12.
Positively or negatively charge atom or (covalently bonded) group of atoms (a molecular ion
Weighted mean mass of an atom of an element compared with 1/12 the mass of an atom of carbon-12.
Weighted mean mass of an atom of a molecule compared with 1/12 the mass of an atom of carbon-12.
Weighted mean mass of a formula unit compared with 1/12 the mass of an atom of carbon-12.
The number of atoms per mole (6.02 X 1023 mol-1)
The amount of any substance containing as many particles as there are carbon atoms in exactly 12g of the carbon-12 isotope.
The mass per mole of a substance. (g mol-1)
The simplest whole-number ratio of atoms of each element present in a compound.
The amount of solute (mol) dissolved in 1dm3 of solution
A solution of a known concentration
The molar relationship between relative quantities of substance taking part in a reaction.
Water molecules that form an essential part of the crystalline structure of a compound.
A substance that contains no water molecules.
A negatively charged subatomic particle which orbits the nucleus at various energy levels. The relative mass of an electron is 1/1836.
A neutral subatomic particle found in the nucleus of an atom. The relative mass of a neutron is 1.
A positively charged subatomic particle found in the nucleus of an atom. The relative mass of a proton is 1.
A compound which is made up of oppositely charged ions that are held together by electrostatic forces.
A measure of the amount of starting materials that end up as useful products. A high atom economy means a process is more sustainable as there is less waste produced.
A gas which has molecules that occupy negligible space with no interactions between them. The ideal gas equation is: pV = nRT.
The volume of 1 mole of gas (units: dm 3 mol -1 ).
Mass per mole of a substance (units: g mol -1 ).
The percentage ratio of the actual yield of product from a reaction compared with the theoretical yield.
In this term the topic of organic chemistry is introduced, students will build on their knowledge of hydrocarbons by learning about isomers and further reactions of alkanes and alkenes that aren't included at GCSE. Students will also gain a basic overview of acids and redox reactions before going on to the study of periodicity; patterns that occur within the periodic table.
A measure of the number of electrons that an atom uses to bond with atoms of another element.
Loss of electrons OR increase in oxidation number
Gain of electrons OR decrease in oxidation number
A reaction in which both reduction and oxidation take place.
A reagent that reduces (adds electrons to) another species.
A reagent that oxidises (takes electrons from) another species.
is the oxidation and reduction of the same element in a redox reaction.
is a chemical reaction in which an acid and a base react together to produce salt and water.
is an acid that fully dissociates in solution
is an acid that partially dissociates in solution.
is a mixture that minimalises the pH changes on addition of small quantities of acid or base.
Students will start this term learning about the reactions of unfamiliar homologous series of organic molecules such as haloalkanes and alcohols. Additionally this term will include the concept of enthalpy; the study of energy changes that occur within reactions. This will entail calculations involving specific heat capacity and Hess' law.
is an acid that fully dissociates in solution
is an acid that partially dissociates in solution.
This is the enthalpy change when an acid is neutralised by an alkali to form a salt and 1 mole of water.
This is the enthalpy change accompanying the complete combustion of 1 mole of the substance under standard conditions. e.g. CH3OH (l) + 1½O2 (g) CO2 (g) + 2H2O (l) H = enthalpy of combustion of methanol
This is the enthalpy change accompanying the formation of one mole of free gaseous atoms from the element in its standard state. e.g. ½Cl2 (g) Cl (g) H = enthalpy of atomisation of chlorine
This is the enthalpy change on hydration of one mole of gaseous ions assuming infinite dilution, i.e. addition of sufficient water so that there is no further enthalpy change upon dilution. e.g. Na+ (g) + aq Na+ (aq) H =
In this term students will develop their synoptic skills by drawing on all organic chemistry topics to explain how organic chemicals can be synthesized from raw materials. Additionally students will learn how to analyse mass spectra and infrared spectra in order to determine the structure of organic molecules. Students will also draw upon knowledge of the factors that affect rate of reaction, and how rate of reaction can be calculated. Finally, the topic of equilibrium will be taught; students will learn how the equilibrium constant relates to the concentration of reactants and products at equilibrium.
Number of protons in the nucleus of an atom
A substance that contains no water molecules.
Loss of electrons OR increase in oxidation number
Gain of electrons OR decrease in oxidation number
A reaction in which both reduction and oxidation take place.
A reagent that reduces (adds electrons to) another species.
is an acid that fully dissociates in solution
The number of moles of a particular component of a mixture divided by the total number of moles present.
The pH of a solution is the negative logarithm to base ten of the molar hydrogen ion concentration. pH = lg [H (aq)]
Rate Constant In the rate expression: rate = k[M]a[N]b, k is called the rate constant
A solution containing a weak acid and its conjugate base, e.g. ethanoic acid and sodium ethanoate.
Students will begin the "2nd year content" to ensure that pace of learning is high. Having just learnt about rates of reaction, students will develop their knowledge here is order to calculate the rate of reaction based on the concentration of reactants. Advanced organic chemistry is approached by introducing students to aromatic chemistry and carboxylic acids.
Water molecules that form an essential part of the crystalline structure of a compound.
A substance that contains no water molecules.
is an acid that fully dissociates in solution
is an acid that partially dissociates in solution.
rate of reaction is the speed at which reactants are converted into products.
a chemical process in which substances act mutually on each other and are changed into different substances, or one substance changes into other substances
This is the enthalpy change when an acid is neutralised by an alkali to form a salt and 1 mole of water.
Students will revise all the topics taught in terms 1 to 4. These are all the topics involved in AS chemistry.