The correct order of increasing bond lengths of $C-H$, $O-H$, $C-C$ and $H-H$ is

The number of electrons in the valence shell of the central atom of a molecule is $8$. The molecule is

The Born-Haber cycle is used to determine:

The incorrect statement$(s)$ regarding $\overset{\bullet }{C}X_{3}$ species is:

Identify the correct statement$(s)$ from the following:
$a$) Dipole moment of $NH_3$ is more than $NF_3$
$b$) $SF_4$ is square planar
$c$) $SnCl_4$ is more covalent than $SnCl_2$
$d$) $In_2SO_4$ sulphur atom has expanded octet

Which of the following is $NOT$ likely to act as a Lewis base?