Consider aqueous solutions of the following coordination compounds: $\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6} \mathrm{I}_{3}, \operatorname{Pt}\left(\mathrm{NH}_{3}\right)_{4} \mathrm{I}_{4}, \mathrm{Na}_{2} \mathrm{Pt}_{6},$ and \(\mathrm{Cr}\left(\mathrm{NH}_{3}\right)_{4} \mathrm{I}_{3}\) . If aqueous AgNO \(_{3}\) is added to separate beakers containing solutions of each coordination compound, how many moles of AgI will precipitate per mole of transition metal present? Assume that each transition metal ion forms an octahedral complex.

: The four coordination compounds are: 1. \(\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6}\mathrm{I}_{3}\): The coordination sphere is \([Co(\mathrm{NH}_{3})_{6}]\), and there are 3 I⁻ ions present. 2. \(\mathrm{Pt}(\mathrm{NH}_{3})_{4} \mathrm{I}_{4}\): The coordination sphere is \([Pt(\mathrm{NH}_{3})_{4}]\), and there are 4 I⁻ ions present. 3. \(\mathrm{Na}_{2} \mathrm{Pt}_{6}\): The coordination sphere is \([Pt(\mathrm{NH}_{3})_{6}]\), and there are 0 I⁻ ions present. 4. \(\mathrm{Cr}(\mathrm{NH}_{3})_{4}\mathrm{I}_{3}\): The coordination sphere is \([Cr(\mathrm{NH}_{3})_{4}]\), and there are 3 I⁻ ions present. Now, we will determine the molar ratio of AgI formed per mole of the transition metal in each compound.

: 1. For \(\mathrm{Co}(\mathrm{NH}_{3})_{6}\mathrm{I}_{3}\), the 3 I⁻ ions will react with 3 moles of AgNO₃ to produce 3 moles of AgI. Therefore, the molar ratio of AgI formed per mole of Co is 3:1. 2. For \(\mathrm{Pt}(\mathrm{NH}_{3})_{4} \mathrm{I}_{4}\), the 4 I⁻ ions will react with 4 moles of AgNO₃ to produce 4 moles of AgI. Therefore, the molar ratio of AgI formed per mole of Pt is 4:1. 3. For \(\mathrm{Na}_{2}\mathrm{Pt}_{6}\), there are no I⁻ ions, and therefore no AgI will precipitate. The molar ratio of AgI formed per mole of Pt is 0:1. 4. For \(\mathrm{Cr}(\mathrm{NH}_{3})_{4}\mathrm{I}_{3}\), the 3 I⁻ ions will react with 3 moles of AgNO₃ to produce 3 moles of AgI. Therefore, the molar ratio of AgI formed per mole of Cr is 3:1. So, the moles of AgI precipitated per mole of transition metal for each coordination compound are as follows: \(\mathrm{Co}(\mathrm{NH}_{3})_{6}\mathrm{I}_{3}\): 3 moles of AgI \(\mathrm{Pt}(\mathrm{NH}_{3})_{4}\mathrm{I}_{4}\): 4 moles of AgI \(\mathrm{Na}_{2}\mathrm{Pt}_{6}\): 0 moles of AgI \(\mathrm{Cr}(\mathrm{NH}_{3})_{4}\mathrm{I}_{3}\): 3 moles of AgI