3 moles of metal complex with formula Co ( en )_2 Cl_3 gives 3 moles of silver chloride on treatment with excess of silver nitrate. The secondary…

$\displaystyle 3$ moles of metal complex with formula $\displaystyle \mathrm{Co}(\mathrm{en})_2 \mathrm{Cl}_3$ gives $\displaystyle 3$ moles of silver chloride on treatment with excess of silver nitrate. The secondary valency of $\displaystyle \mathrm{Co}$ in the complex is \_\_\_\_. (Round off to the Nearest Integer).