If excess of ${\mathrm{AgNO}}_3$ solution is added to 100 mL of a 0.024 M solution of dichlorobis (ethylene diamine cobalt (III) chloride, how many $\mathrm{mol}$ of $\mathrm{Agcl}$ be precipitated?

Each complex molecule only releases one  ${\mathrm{CI}}^{-}$, which precipitates as  $\mathrm{Agcl}$ 

$100 \mathrm{mL}$ of $0.024\mathrm{M}$ complex $=0.024\mathrm{mol}/\mathrm{L}\times \frac{100\mathrm{mL}}{1000\mathrm{mL}/\mathrm{L}}=0.0024\mathrm{mol}$

The number of moles of $\mathrm{Agcl}$ formed = the number of moles of complex $0.024\mathrm{M}$ $\mathrm{mol}$

$\begin{array}{l}\left[{\mathrm{CoCl}}_2(\mathrm{en}{)}_2\right]\mathrm{Cl}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}+{\mathrm{AgNO}}_3\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}⟶\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\mathrm{AgCl}\downarrow \\ \hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}100\times 0.024=2.4\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}2.4\mathrm{mol}\end{array}$

Hence correct option is C.