A-LevelChemistryAnalytical techniquesOct/Nov 2025Paper 1 Q351 Mark
The structure of a naturally occurring compound, Q, is shown. [Figure 35: Compound Q structure] Compound Q is heated under reflux with an excess of acidified KMnO4. Organic product R is formed. Which row is correct?
Aorange precipitate with 2,4-DNPH and no reaction with alkaline I2(aq); yellow precipitate with alkaline I2(aq) and no reaction with Fehling's reagent
Bred precipitate with Fehling's reagent and no reaction with alkaline I2(aq); orange precipitate with 2,4-DNPH and no reaction with alkaline I2(aq)
Cyellow precipitate with alkaline I2(aq) and orange precipitate with 2,4-DNPH; no reaction with alkaline I2(aq) and no reaction with Fehling's reagent
Dyellow precipitate with alkaline I2(aq) and red precipitate with Fehling's reagent; yellow precipitate with alkaline I2(aq) and orange precipitate with 2,4-DNPH
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The correct answer is B. This question tests the candidate's understanding of analytical techniques within the Chemistrysyllabus. The examiner's mark scheme requires...
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