A-LevelChemistryChemical bondingFeb/Mar 2016Paper 1 Q191 Mark
After black and white photographic film has been developed, unreacted silver bromide is removed by reaction with sodium thiosulfate. AgBr + 2Na₂S₂O₃ → 4Na⁺ + Br⁻ + [Ag(S₂O₃)₂]³⁻ What is the function of the thiosulfate ion?
Ato make the silver ions soluble
Bto oxidise the silver ions
Cto reduce the bromine
Dto reduce the silver ions
✓ Correct Answer
The correct answer is A. This question tests the candidate's understanding of chemical bonding 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...
🔒
Unlock the Examiner's Answer
Sign up for free to reveal the correct answer, the official mark scheme breakdown, and the examiner trap analysis for this question.
Sign Up Free to Unlock →Join thousands of Cambridge students already using Oracle Prep