Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :
- Both Statement I and Statement II are true
- Both Statement I and Statement II are false
- Statement I is false but Statement II is true
- Statement I is true but Statement II is false
Answer
(4) Statement I is true but Statement II is false
Solution
Statement I: Bond dissociation enthalpy ( kJ mol-1): Cl2 242.6, Br2 192.8, F2 158.8, I2 151.1
F2 has an unusually low value due to large repulsion between the lone pairs of the small F atoms.
Cl2 > Br2 > F2 > I2. Statement I is true.
Statement II: A metal ion in a higher oxidation state has greater polarising power, so its halide is more covalent.
As per NCERT, SnCl4, PbCl4 and UF6 are more covalent than SnCl2, PbCl2 and UF4.
The trend UF4 > UF6 is wrong. Statement II is false.
Answer: (4)