The formal charges on the atoms marked as $(1)$ to $(4)$ in the Lewis representation of $HNO_3$ molecule respectively are

The incorrect statement is :-

Which one of the following is not correct?

Identify the thermal decomposition reactions that evolve a gas containing an equal number of $\sigma$ and $\pi$ bonds.
$(a)$ $BeCO_3 \xrightarrow{\Delta } BeO + CO_2$
$(b)$ $Fe_2(SO_4)_3 \xrightarrow{\Delta } Fe_2O_3 + 3SO_3$
$(c)$ $FeSO_4 \xrightarrow{\Delta } Fe_2O_3 + SO_2 + SO_3$
$(d)$ $(NH_4)_2Cr_2O_7 \xrightarrow{\Delta } Cr_2O_3 + N_2 + 4H_2O$
$(e)$ $ZnSO_4 \xrightarrow{\Delta } ZnO + SO_3$
$(f)$ $NH_4Cl \xrightarrow{\Delta } NH_3 + HCl$

Which of the following species contains an equal number of $\sigma -$ and $\pi -$ bonds?

For the following molecules/ions,identify whether the octet rule is obeyed or not obeyed. Provide the reason.
$(1)$ $PCl_5$ $(2)$ $SF_6$ $(3)$ $PF_5$ $(4)$ $NH_4^+$ $(5)$ $BeCl_2$ $(6)$ $NCl_3$