Q1. [1]
When aqueous solutions of potassium iodide and lead nitrate are mixed, an insoluble substance separates out. The chemical equation for the reaction involved is :
- (a) KI + PbNO₃ → PbI + KNO₃
- (b) 2KI + Pb(NO₃)₂ → PbI₂ + 2KNO₃
- (c) KI + Pb(NO₃)₂ → PbI + KNO₃
- (d) KI + PbNO₃ → PbI₂ + KNO₃
Previously asked in CBSE board exam
2023 31/4/1 Q2
Generated by claude-sonnet-4-6 · 2026-06-14 10:29 · grounding rag
Model Answer
(b) 2KI + Pb(NO₃)₂ → PbI₂ + 2KNO₃
Explanation
This is a double displacement (precipitation) reaction. Lead iodide (PbI₂) is the yellow insoluble precipitate. The equation must be balanced — 2 units of KI are needed to provide 2 iodide ions for one Pb²⁺ ion, making option (b) the only correctly balanced equation.
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