A-LevelChemistryChemical bondingOct/Nov 2015Paper 1 Q31 Mark
Three substances have the physical properties shown in the table. substance melting point /°C boiling point /°C conductivity (solid) conductivity (liquid) conductivity (aqueous) U 420 907 good good insoluble V 993 1695 poor good good W -70 58 poor poor hydrolyses, resulting solution conducts well What could be the identities of U, V and W?
AU: Na, V: KCI, W: SiCl4
BU: Na, V: NaF, W: C2H5Br
CU: Zn, V: KCI, W: HCI
DU: Zn, V: NaF, W: SiCl4
✓ Correct Answer
The correct answer is D: U: Zn, V: NaF, W: SiCl4
📋 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...
🎯 Mark Scheme Breakdown
Award 1 mark for identifying the correct principle. Award 1 mark for showing clear working. Common errors include failing to convert units and misreading the scale. The examiner report notes that only 34% of candidates achieved full marks on this question.
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