C5: Oxidation, Reduction and Redox Reactions
Official Cambridge & Imperial ESAT specification requirements for Oxidation, Reduction and Redox Reactions on the Chemistry paper. Understand the syllabus boundaries, spot distractor traps engineered by examiners, and master the 2-step Sub-90 shortcuts that compress solve time well below the 88.8-second cutoff.
Official Syllabus Subtopics
Requirements specified in the UAT-UK framework
- 1OIL RIG: Oxidation Is Loss of electrons, Reduction Is Gain of electrons
- 2Oxidation state rules: uncombined = 0, Group 1 = +1, Group 2 = +2, F = -1, O = -2, H = +1
- 3Balancing complex redox equations and ionic half-equations
- 4Disproportionation reactions: single element simultaneous oxidation and reduction
- 5Identifying oxidising agents (reduced) and reducing agents (oxidised)
Sub-90 Exam Speed Tips
How top candidates solve this spec under the 88.8s clock
An oxidising agent oxidises another species and is itself reduced (its oxidation number decreases).
In disproportionation reactions, look for a reactant element whose oxidation state both rises and falls.
Examiners engineer distractor options using common algebraic expansions and sign slips. Always test structural ratios or invariants before calculating arithmetic values.
Tested Topics in Specification C5
Master the individual question patterns and Sub-90 shortcuts for this specification.
Oxidation State Assignment, Redox Disproportionation & Ionic Half-Equation Balancing
For disproportionation, look for a free element (e.g. Cl2, Br2, Cu+) or intermediate oxide (NO2, H2O2) on the LEFT that appears in TWO different products on the RIGHT with one higher and one lower oxidation state.
Ready to Master Specification C5 Under Exam Conditions?
Practice timed questions under the authentic Pearson VUE interface with live split stopwatch pacing, dry-wipe scratchpad, and distractor forensics.