the concept of amount of substance in performing calculations involving atom economy;
the relationship between atom economy and the efficient use of atoms in a reaction

the explanation (given the necessary information) of the chemical processes occurring during the extraction of the halogens from minerals in the sea

Recall of processes not required.

techniques and procedures in the electrolysis of aqueous solutions;
half-equations for the processes occurring at electrodes in electrolysis of molten salts and aqueous solutions:

(i) formation of oxygen or a halogen or metal ions at the anode
(ii) formation of hydrogen or a metal at the cathode

Cathode description in aqueous electrolysis: ‘Group 1 and 2 and aluminium salts give hydrogen, other metals are plated’.

redox reactions of s-, p- and d-block elements and their compounds in terms of electron transfer:

(i) use of half-equations to represent simple oxidation and reduction reactions
(ii) the definition of oxidation and reduction as loss and gain of electrons
(iii) identification of oxidising and reducing agents

Recall of specific reactions is only needed if required elsewhere, e.g. ES(j).
‘Simple’ means not involving acid–base, see also ES(f).

the oxidation states assigned to and calculated for specified atoms in formulae (including ions) and explanation of which species have been oxidised and which reduced in a redox reaction

use of oxidation states to balance redox equations that do not also involve acid–base reactions;
techniques and procedures in iodine-thiosulfate titrations

e.g. \(3Ca + 2Al^{3+} → 3Ca^{2+} + 2Al\)
but not: \(MnO_4^- + 5Fe^{2+} + 8H^+ → Mn^{2+} + 5Fe^{3+} + 4H_2O\)
See also DM(c).

use of systematic nomenclature to name and interpret the names of inorganic compounds

e.g. copper(I) sulfide, sodium chlorate(I), lead(II) nitrate(V), potassium manganate(VII) but not complex ions.

a description of the following physical properties of the halogens: appearance and physical state at room temperature, volatility, solubility in water and organic solvents

Explanation not required.
See also OZ(d)

the relative reactivities of the halogens in terms of their ability to gain electrons

the details of the redox changes which take place when chlorine, bromine and iodine react with other halide ions, including observations, equations and half-equations

the reactions between halide ions (Cl^-, Br^- and I^-) and silver ions (Ag⁺) and ionic equations to represent these precipitation reactions, the colours of the precipitates and the solubility of silver halides in ammonia

the preparation of HCl;
the preparation of HBr and HI by using the halide and phosphoric acid;
the action of sulfuric acid on chlorides, bromides and iodides

Details of phosphoric acid (and equations involving it) are not required.

the properties of the hydrogen halides: different thermal stabilities, similar reaction with ammonia and acidity, different reactions with sulfuric acid

Sulfuric acid is reduced to SO₂ by HBr and H₂S by HI.

the risks associated with the storage and transport of chlorine;
uses of chlorine which must be weighed against these risks, including: sterilising water by killing bacteria, bleaching

the characteristics of dynamic equilibrium

the equilibrium constant, K_c for a given homogeneous reaction;
calculations of the magnitude of K_c and equilibrium concentrations using data provided;
relation of position of equilibrium to size of K_c, using symbols such as >, <, >>, <<

Units will not be required.
See also CI(h).

the use of K_c to explain the effect of changing concentrations on the position of a homogeneous equilibrium;
extension of the ideas of ‘opposing change’ to the effects of temperature and pressure on equilibrium position

e.g. ‘if a concentration term on the top becomes larger, one on the bottom must also become larger to keep K_c constant, so equilibrium position moves to the left’.