Q125P - Chemistry: Molecular Nature Of Matter And Change

Question

An octahedral complex with three different ligands can have formulas with three different ratios of the ligands: 

${\left[{\text{MA}}_4\text{BC}\right]}^{4+}$, such as ${\left[\text{Co}{\left({\text{NH}}_3\right)}_4\left({\text{H}}_2\text{O}\right)\text{Cl}\right)}^{2+}$

$\left[{\text{MA}}_3{\text{B}}_2{\text{C}}^{2+}\right.$, such $\left[\text{Cr}{({\text{H}}_2\text{O}⟩}_3{\text{Br}}_2\text{Cl}\right]$

${\left[{\text{MA}}_2{\text{B}}_2{\text{C}}_2\right]}^{*+}$, such as $\left[\text{Cr}{\left({\text{NH}}_3\right)}_2{\left({\text{H}}_2{\text{O}}_2{\text{Br}}_2\right]}^{+}\right.$

Step-by-Step Solution

Answer

(I) tetraammineaquachlorocobalt (III), with cis/trans isomers;

(2) aquatribromodichlorochromium(III), with fac/mer isomers;

(3) diamminediaquadibromochromium(III), with cis/trans isomers;

Step 1: Given information

The given information is to find the formula of coordination compounds.

Step 3: Solve the given statements

In naming coordinate compounds, it is important to follow conventions:

- Cations are named before anions

- The ligands are arranged alphabetically

- The name of the metal ion comes last, while the charge of the ion must be enclosed in parenthese

- When the overall charge of the complex ion is negative, the metal must end in -ate

${\left[{\text{MA}}_{4}BC\right]}^{n+}:{\left[\text{Co}{\left({\text{NH}}_3\right)}_4\left({\text{H}}_2\text{O}\right)\text{Cl}\right]}^{2+}$

Ligands:$\left(4{\text{NH}}_3\right)$ ammine,$\left(1{\text{H}}_2\text{O}\right)$ aqua,$\left(1{\text{Cl}}^{-}\right)$ chloro

Name: tetraammineaquachlorocobalt(III)

Isomers: Geometric Isomers.

 

 

 

${\left[{\text{MA}}_3{\text{B}}_2\text{C}\right]}^{\text{n}+}:\left[\text{Cr}{\left({\text{H}}_2\text{O}\right)}_3\text{BrCl}\right]$

Ligands: (3$\left.{\text{Br}}^{-}\right)$  bromo,$\left({\text{H}}_2\text{O}\right)$ aqua, (2$\left.{\text{Cl}}^{-}\right)$ chloro

Name: aquatribromodichlorochromium(III)

Isomers: Fac/Mer isomers

 

${\left[{\text{MA}}_2{\text{B}}_2{\text{C}}_2\right]}^{\text{n}+}:{\left[\text{Cr}{\left({\text{NH}}_3\right)}_2{\left({\text{H}}_2\text{O}\right)}_2{\text{Br}}_2\right]}^{+}$

Ligands: ammine, aqua, bromo

Name: diamminediaquadibromochromium(III)

Isomers: cis/trans isomers