A-Level Chemistry revision notes

A-Level (A2/AS) Chemistry revision notes providing information and assistance across all examination boards including AQA, CIE, OCR, Edexcel, Eduqas & WJEC. Chemistry is a complicated A-Level with a lot of content and information to work through. We have put together some of the best revision notes and learning materials to hopefully make sitting your Chemistry A-Levels a little bit easier and stress-free.

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Aromatic Compounds

Key Summary & Facts Aromatic compounds are planar cyclic structures in which each atom of the ring is a participant in a pi bond, The pi electrons or aromatic compound delocalized around the ring Cyclic aromatic compounds undergo to electrophilic substitution reactions A compound is aromatic if they have 4n+2 delocalised electrons Benzene is highly ...

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Acids, Bases and Buffers

-Brønsted-Lowry acids are proton donors and bases are proton acceptors. -In water, an acid can donate a proton to form aqueous H+ and the conjugate base; a base can accept a proton from water to form OH– and the conjugate acid. -A buffer solution makes able to add a strong acid or base to a ...

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Redox Reaction

A redox is a type of chemical reaction that involves a transfer of electrons between two species The oxidation state of an element corresponds to the number of electrons, that an atom loses, gains in a chemical reaction The reducing agent is the reactant that is being oxidized The oxidizing agent is reactant that is ...

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Key Facts & Summary Halogen have very high electronegativities They have seven valence electrons (one short of a stable octet) They are highly reactive, therefore toxics The halogens are Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I) and Astatine (At) Down the group, atom size increases. Halogens are a group of elements on the periodic ...

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Key Facts & Summary Halogenoalkanes are compounds in which one or more hydrogen atoms in an alkane have been replaced by halogen atoms (fluorine, chlorine, bromine or iodine). They are also named haloalkanes or alkyl halides. They can be divided into primary, secondary and tertiary halogenoalkanes based on the number of substitutions of C which ...

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Enthalpy Changes

Key Facts & Summary The enthalpy of a chemical system refers to the "heat content" of the system. Enthalpy is given the symbol H Enthalpy change refers to the amount of heat released or absorbed when a chemical reaction and it is given the symbol ΔH A reaction is exothermic when it releases energy, and ...

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Electron Structure

Key Facts & Summary Lewis structures are diagrams that show the bonding between atoms of a molecule and the lone pairs of electrons. The electronic structure is the arrangement of electrons in energy levels around an atomic nucleus The s orbital can be occupied by no more than a pair of electrons. The p orbital ...

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Chemical Equilibrium

Key Facts & Summary Chemical equilibrium is defined as the dynamic condition reached by a reversible reaction when the direct reaction and the inverse reaction occur simultaneously. A reversible reaction can proceed in both forward and backward directions. Equilibrium is reached when the rate of the forward reaction equals the rate of the reverse reaction. ...

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Bonds and Structures

Key Facts & Summary There are 4 main chemical bonds: ionic, covalent, polar and hydrogen bond. Electronegativity is the property of an atom to attract a shared pair of electrons (or electron density) towards itself. An ionic bond involves a transfer of an electron between two atoms A covalent bond involves the sharing of electrons ...

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