Decreasing order of reactivity towards electrophilic substitution for the following compounds is :

For a reversible reaction $\mathrm{A} \rightleftharpoons \mathrm{B}$, the $\Delta \mathrm{H}_{\text{forward reaction}} = 20 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The activation energy of the uncatalysed forward reaction is $300 \mathrm{~kJ} \mathrm{~mol}^{-1}$. When the reaction is catalysed keeping the reactant concentration same, the rate of the catalysed forward reaction at $27^{\circ} \mathrm{C}$ is found to be same as that of the uncatalysed reaction at $327^{\circ} \mathrm{C}$.

The activation energy of the catalysed backward reaction is ___________ $\mathrm{kJ}~ \mathrm{mol}^{-1}$.

The volume (in $\mathrm{mL}$) of $0.1 \mathrm{M} ~\mathrm{AgNO}_{3}$ required for complete precipitation of chloride ions present in $20 \mathrm{~mL}$ of $0.01 \mathrm{M}$ solution of $\left[\mathrm{Cr}\left(\mathrm{H}_{2} \mathrm{O}\right)_{5} \mathrm{Cl}\right] \mathrm{Cl}_{2}$ as silver chloride is __________.

The number of correct statements from the following is _______.

(A) Conductivity always decreases with decrease in concentration for both strong and weak electrolytes.

(B) The number of ions per unit volume that carry current in a solution increases on dilution.

(C) Molar conductivity increases with decrease in concentration

(D) The variation in molar conductivity is different for strong and weak electrolytes

(E) For weak electrolytes, the change in molar conductivity with dilution is due to decrease in degree of dissociation.