The species having the maximum $Cl-O$ bond order is:

Identify the correct orders against the property mentioned:
$(A)$ $H_2O > NH_3 > CHCl_3$ - dipole moment
$(B)$ $XeF_4 > XeO_3 > XeF_2$ - number of lone pairs on central atom
$(C)$ $O-H > C-H > N-O$ - bond length
$(D)$ $N_2 > O_2 > H_2$ - bond enthalpy
Choose the correct answer from the options given below:

Which of the following fluoro compounds acts as a Lewis base?

Which of the following molecules has the weakest $(p \pi - d \pi)$ back bonding?

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

The number of $S-S$ bonds in sulphur trioxide trimer $(S_3O_9)$ is