The ratio of lone pair of electrons to bond pair of electrons in ozone molecule is

Identify the number of molecules in which the central atom has one lone pair of electrons from the following list.

$$ \mathrm{PbCl}_2, \mathrm{PH}_3, \mathrm{ClF}_3, \mathrm{SF}_4, \mathrm{BF}_3, \mathrm{SnCl}_2 $$

In which of the following molecules, the number of lone pairs of electrons on central atom and the number of $d$-orbitals involved in the hybridisation of central atom, is same?

From the following, identify the ions with same bond order.

I. $\mathrm{CN}^{-} \quad$ II. $\quad \mathrm{N}_2^{+}$

III. $\mathrm{O}_2^{2-}$ IV. $\mathrm{NO}^{+}$