A-Level Chemistry OCR A H432

explanation and use of the terms oxidising agent and reducing agent (see also 2.1.5 Redox)

construction of redox equations using half-equations and oxidation numbers

interpretation and prediction of reactions involving electron transfer

the techniques and procedures used when carrying out redox titrations including those involving Fe²⁺/MnO₄^– and I₂/S₂O₃²⁻ (see also 2.1.5e–f)

structured and non-structured titration calculations, based on experimental results of redox titrations involving:

(i) Fe²⁺/MnO₄^– and I₂/S₂O₃²⁻ (ii) non-familiar redox systems

Non-structured titration calculations could be examined in the context of both acid–base and redox titrations (see also 2.1.4d–e).

use of the term standard electrode (redox) potential, E^θ, including its measurement using a hydrogen electrode

E^θ data will be provided on examination papers.

the techniques and procedures used for the measurement of cell potentials of:

(i) metals or non-metals in contact with their ions in aqueous solution (ii) ions of the same element in different oxidation states in contact with a Pt electrode

For measurement of standard cell potentials, ions of the same element can have concentrations of 1 mol dm^–3 or be equimolar. PAG8

calculation of a standard cell potential by combining two standard electrode potentials

prediction of the feasibility of a reaction using standard cell potentials and the limitations of such predictions in terms of kinetics and concentration

application of principles of electrode potentials to modern storage cells

Details of storage cells and required equations will be provided. Relevant electrode potentials and other data will be supplied.

explanation that a fuel cell uses the energy from the reaction of a fuel with oxygen to create a voltage and the changes that take place at each electrode.

Recall of fuel cells and equations will not be required. Relevant electrode potentials and other data will be supplied.