## Chemistry: Molecular Approach (4th Edition)

a. Hexaaquanickel (II) chloride : $\left[ Ni{{\left( {{H}_{2}}O \right)}_{6}}C{{l}_{2}} \right]$ b. Pentacarbonylchloromanganese(I) : $\left[ (Mn\text{ }{{\left( CO \right)}_{5}}Cl \right]$ c. Ammonium diaquatetrabromovanadate(III): ${{\left( N{{H}_{4}} \right)}_{2}}\left[ V{{\left( {{H}_{2}}O \right)}_{2}}{{\left( Br \right)}_{4}} \right]$ d. Tris(ethylenediamine)cobalt(III) trioxalatoferrate(III): $\left[ Co{{\left( en \right)}_{3}} \right]\text{ }\left[ Fe{{\left( ox \right)}_{3}} \right]$
a. Hexaaquanickel (II) chloride The name indicates that the complex cation is hexaaquanickel (II). While writing the name of a coordination compound, the name of the cation comes before the anion. The anion is $C{{l}^{-}}.$ The central metal ion of the complex cation is $N{{i}^{+2}}$. The ligand is ${{H}_{2}}O$ as indicated by the name hexaaquanickel (II) and there are $6\text{ }{{H}_{2}}O$groups coordinated to the central Ni atom. ${{H}_{2}}O$ is a neutral ligand, so the charge on the central metal ion will be the charge on the complex cation. Therefore, the formula for the complex cation is $Ni{{\left( {{H}_{2}}O \right)}_{6}}^{+2}$; hence, the complete formula for the compound is $\left[ Ni{{\left( {{H}_{2}}O \right)}_{6}}C{{l}_{2}} \right]$. b. Pentacarbonylchloromanganese (I) The name suggests that the ligands coordinated with the central metal atom manganese are $CO,$ carbonyl group, and $C{{l}^{-}}$group. CO is a neutral ligand, and it’s an anionic ligand. The charge on the central metal atom Mn is given to $be\text{ }+\text{ }1$. Therefore, the formula for the compound is $\left[ (Mn\text{ }{{\left( CO \right)}_{5}}Cl \right]$. c. Ammonium diaquatetrabromovanadate (III) The name suggests that diaquatetrabromovanadate (III) is the complex anion. When writing the name of a coordination compound, the name of cation comes before the anion and if the complex is an anion, the name of the central metal ion ends with ‘ate.’ The cation is ammonium $N{{H}_{4}}^{+}$. The central metal ion of the complex anion is $+3$. The ligands are ${{H}_{2}}O$and $B{{r}^{-}}$. diaquatetrabromovanadate (III) and there are $2\text{ }{{H}_{2}}O$and$~4\text{ }B{{r}^{-}}$ groups coordinated to the central V atom. ${{H}_{2}}O$ is a neutral ligand and $B{{r}^{-}}$ is a negative anionic ligand. Therefore, the formula for the complex anion is ${{\left[ V{{\left( {{H}_{2}}O \right)}_{2}}{{\left( Br \right)}_{4}} \right]}^{-2}}$. Hence, the complete formula for the compound is ${{\left( N{{H}_{4}} \right)}_{2}}\left[ V{{\left( {{H}_{2}}O \right)}_{2}}{{\left( Br \right)}_{4}} \right]$. d. Tris(ethylenediamine)cobalt (III) trioxalatoferrate (III) The name suggests that the complex cation of the compound is ${{\left( CO{{\left( en \right)}_{3}} \right)}^{+3}}$. The complex anion of the compound is $~{{\left( Fe{{\left( ox \right)}_{3}} \right)}^{-3}}$. The formula of the compound is $\left[ Co{{\left( en \right)}_{3}} \right]\text{ }\left[ Fe{{\left( ox \right)}_{3}} \right]$.