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Statement-1: PbI4 is not stable and spontaneously decomposes into PbI2 and I2 at room temperature, whereas PbCl4 requires heating to break down into PbCl2 and Cl2. Statement-2: Owing to the inert pair effect, the +2 oxidation state of lead is more stable than the +4 state. Choose the correct option regarding the two statements.

1. Statement-1 is true, Statement-2 is true, and Statement-2 is the correct explanation of Statement-1.
2. Statement-1 is true, Statement-2 is true, but Statement-2 is NOT the correct explanation of Statement-1.
3. Statement-1 is true, Statement-2 is false.
4. Statement-1 is false, Statement-2 is true.

Correct answer: Statement-1 is true, Statement-2 is true, but Statement-2 is NOT the correct explanation of Statement-1.

Solution

Pb4+ is a strong oxidiser and I- is a strong reducing/easily oxidised anion, so Pb4+ oxidises I- to I2, making PbI4 nonexistent; Cl- is less easily oxidised so PbCl4 survives until heated. Both statements are true, but the inert pair effect is only part of the story (the redox incompatibility of Pb4+ with I- is key), so Statement-2 is not the complete explanation.

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