Choose the correct statement:

Consider the following reactions:
$(i)$ $PCl_3 + 3H_2O \to H_3PO_3 + 3HCl$
$(ii)$ $SF_4 + 3H_2O \to H_2SO_3 + 4HF$
$(iii)$ $BCl_3 + 3H_2O \to H_3BO_3 + 3HCl$
$(iv)$ $XeF_6 + 3H_2O \to XeO_3 + 6HF$
Then according to given information the incorrect statement is

"Hybridisation of central atom does not always change due to back bonding". This statement is valid for which of the following compounds?
$(i)$ $CCl_3^-$ $(ii)$ $CCl_2$ $(iii)$ $(SiH_3)_2O$ $(iv)$ $N(SiH_3)_3$

Choose the correct code of characteristics for the given order of hybrid orbitals of the same atom,$sp < sp^2 < sp^3$:
$(i)$ Electronegativity
$(ii)$ Bond angle between same hybrid orbitals
$(iii)$ Size
$(iv)$ Energy level

Explain bond formation in $BCl_{3}$. It is a symmetrical trigonal molecule.

In which of the following molecules the central atom does not have $sp^3$ hybridization?