O-LevelChemistryAcids, Bases & Salts5070/11 · May/June 2014 · Q111 Mark

Aqueous potassium iodide, KI(aq), can be used as a test reagent in redox reactions. Iodide ions are readily ......X...... . A positive result for the test is when the solution changes colour from ......Y...... to ......Z...... Which words correctly complete gaps X, Y and Z?

AX: oxidised, Y: brown, Z: colourless

BX: oxidised, Y: colourless, Z: brown

CX: reduced, Y: brown, Z: colourless

DX: reduced, Y: colourless, Z: brown

✓ Correct answer

B: X: oxidised, Y: colourless, Z: brown

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Topic: Acids, Bases & Salts, O-Level Chemistry (syllabus 5070). Multiple choice, 1 mark.
Source: O-Level Chemistry, May/June 2014 Paper 1 Variant 1, question 11.

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