A-LevelChemistryAtoms, molecules and stoichiometryMay/June 2025Paper 1 Q51 Mark
'Red lead' is a red pigment with the formula Pb3O4. Every formula unit of 'red lead' is the same. Each formula unit contains three lead ions and four oxide ions. Lead has two different oxidation states in 'red lead'. What are the oxidation states of lead in 'red lead'?
A+1 and +2
B+1 and +3
C+2 and +4
D+2 and +6
✓ Correct Answer
The correct answer is C. This question tests the candidate's understanding of atoms, molecules and stoichiometry within the Chemistrysyllabus. The examiner's mark scheme requires...
📋 Examiner Report & Trap Analysis
Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...
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