$$ \begin{aligned} & \mathrm{Ag}^{+}+\mathrm{NH}_3 \quad\left[\mathrm{Ag}\left(\mathrm{NH}_3\right)\right]^{+} \\ & k_1=3.5 \times 10^{-3} \\ & {\left[\mathrm{Ag}\left(\mathrm{NH}_3\right]^{+}+\mathrm{NH}_3 \quad\left[\mathrm{Ag}\left(\mathrm{NH}_3\right)_2\right]^{+}\right.} \end{aligned} $$

$k_2=1.7 \times 10^{-3}$, then the formation constant of $\left[\mathrm{Ag}\left(\mathrm{NH}_3\right)_2\right]^{+}$ is :

$\mathrm{CH}_3 \mathrm{NH}_2+\mathrm{CHCl}_3+\mathrm{KOH} \rightarrow$ Nitrogen containing compound $+\mathrm{KCl}+\mathrm{H}_2 \mathrm{O}$.

Nitrogen containing compound is :

$\mathrm{CuSO}_4$ decolourises on addition of KCN , the product is

The direct conversion of A to B is difficult; hence, it is carried out by the following shown path:Given,

$$ \begin{aligned} & \Delta \mathrm{S}_{(\mathrm{A} \rightarrow \mathrm{C})}=50 \text { e.u. } \\ & \Delta \mathrm{S}_{(\mathrm{C} \rightarrow \mathrm{D})}=30 \text { e.u. } \\ & \Delta \mathrm{S}_{(\mathrm{B} \rightarrow \mathrm{D})}=20 \text { e.u. } \end{aligned} $$

Where e.u. is entropy unit. Then $\Delta \mathrm{S}_{(\mathrm{A} \rightarrow \mathrm{B})}$ is :