Chemistry - Ionic Equilibrium Question with Solution | TestHub

${\mathrm{Ag}}^{2+}+2{\mathrm{NH}}_3\rightleftharpoons \mathrm{Ag}{\left({\mathrm{NH}}_3\right)}_2{}^{+}$

$0.8-\mathrm{x}\mathrm{z}-2\mathrm{x}\mathrm{x}$ ;

${\mathrm{k}}_{\mathrm{f}}=10^8$; so $\mathrm{x}\approx 0.8$

$5\times 10^{-8}\mathrm{z}-0.8\times 20.8$

${\mathrm{k}}_{\mathrm{f}}=\frac{\left[\mathrm{Ag}{\left({\mathrm{NH}}_3\right)}^{+}\right]}{\left[{\mathrm{Ag}}^{+}\right]{\left[{\mathrm{NH}}_3\right]}^2}=\frac{0.8}{5\times 10^{-8}(\mathrm{z}-1.6{)}^2}=10^8$

$(\mathrm{z}-1.6{)}^2=0.16$;

$\mathrm{z}-1.6=0.4;$

$\mathrm{z}=2$

Initial concentration $\frac{\mathrm{n}}{\mathrm{V}}=2(\because \mathrm{V}=2$ litre $)$;

$\therefore \mathrm{n}=4$ litre]