The number of $Cl=O$ bonds in perchloric acid is:

Which of the following statements are true?

Which of the following molecules contains both ionic and covalent bonds?

Observe the following species:
$(i)$ $NH_3$
$(ii)$ $AlCl_3$
$(iii)$ $SnCl_4$
$(iv)$ $CO_2$
$(v)$ $Ag^{+}$
$(vi)$ $HSO_4^{-}$
How many of the above species act as Lewis acids?

The ionic bond is absent in

In the $OF_2$ molecule,the number of bonding and lone pairs of electrons are,respectively,........