R3
Mechanisms of Chemical Change
Proton transfer, electron transfer, and how chemical bonds rearrange.
R3.1 Proton Transfer
Brønsted-Lowry acids/bases, pH, Kw, calculations.
→R3.2 Electron Transfer
Redox reactions, oxidation states, activity series, cells.
→R3.3 Electron Sharing
Nucleophilic substitution, addition, electrophilic substitution.
→R3.4 Electron-pair Sharing HL
Lewis acids and bases, transition metal complexes.
→Exam Practice
Exam-style questions with mark schemes, examiner tips, and cross-topic links. Each page covers MCQs, data analysis and structured questions.
R3.1 Proton Transfer
12 questions · Acid-base chemistry and buffer calculations
R3.2 Electron Transfer HL
14 questions · Redox titration, electrochemical & electrolysis cells
R3.3 Electron Sharing HL
11 questions · Organic reaction mechanism types
R3.4 Electron-pair Sharing HL
10 questions · Lewis structures and complex ions