For the reaction given below: CoCl 3 .   xNH 3 + AgNO 3 aq → If two equivalents of AgCl…

${\mathrm{CoCl}}_{3.}{\mathrm{xNH}}_3+{\mathrm{AgNO}}_3\to \underset{2 \mathrm{mol}}{\mathrm{AgCl}\downarrow }$

For 2 moles of AgCl precipitate out,only two chloride ions should be present out side the coordination sphere that is in the ionization sphere.

Hence, the formula of the complex should be $\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_5\mathrm{Cl}\right]{\mathrm{Cl}}_2$

$\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_5\mathrm{Cl}\right]{\mathrm{Cl}}_2+{\mathrm{AgNO}}_3\to \underset{2 \mathrm{mol}}{\mathrm{AgCl}\downarrow }$

So, the value of x should be 5.

$\mathrm{x}=5$.