Question: 47: Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): ICI is more reactive than I2.
Reason (R): I-CI bond is weaker than I-I bond.
In the light of the above statements, choose the most appropriate answer from the options given below:
(1) (A) is correct but R is not correct
(2) (A) is not correct but (R) is correct
(3) Both (A) and (R) are correct and (R) is the correct explanation of (A).
(4) Both (A) and (R) are correct but (R) is not the correct explanation of (A).
Answer: Option (3)
Explanation:
ICI is an interhalogen compound, while I2 is a homonuclear diatomic molecule.
Interhalogen compounds are generally more reactive than halogen molecules because the bond between two different halogen atoms is weaker.
The I–Cl bond in ICI is weaker than the I–I bond in iodine due to difference in size and electronegativity between iodine and chlorine atoms.
A weaker bond requires less energy to break, making ICI more reactive compared to I2.
Hence, Assertion (A) is correct.
Since the increased reactivity of ICI is directly due to the weaker I–Cl bond compared to the I–I bond,
Reason (R) is also correct and correctly explains the assertion.