In which of the following cases C-C bond length will be highest? (I) In N_(2)F_(4), d-orbitalsare contracted by electronegative flourine atoms, but d-orbitals contraction is not possible by H-atoms in N_(2)H_(4) (II) The N-N bond energy in N_(2)F_(4) is more than N-N bond energy in N_(2)H_(4) (III) The N-N bond lengthin N_(2)F_(4) is more than that of in N_(2)F_(4) (IV) The N-N bond length in N_(2)F_(4) is less than that of in N_(2)H_(4) choose the correct codes:

In which of the following cases C-C bond length will be highest? (I)

1.	In which of the following cases C-C bond length will be highest? (I) In N_(2)F_(4), d-orbitalsare contracted by electronegative flourine atoms, but d-orbitals contraction is not possible by H-atoms in N_(2)H_(4) (II) The N-N bond energy in N_(2)F_(4) is more than N-N bond energy in N_(2)H_(4) (III) The N-N bond lengthin N_(2)F_(4) is more than that of in N_(2)F_(4) (IV) The N-N bond length in N_(2)F_(4) is less than that of in N_(2)H_(4) choose the correct codes:
Answer» I, II and III I and III II and IV II and III Solution : It can be explained on the basis of Bent's Rule . In `N_(2)F_(4)`, N-N bond has more s-character hence bond length decrease. While in `N_(2)H_(4), N-N` bond has less s-character (i.e., more p-character), hence bond LENGTHS.