Question

Give the IUPAC name of the complex compound $\left[Co{\left(N{H}_3\right)}_4\left(H_{2}O\right)Br\right]{\left(N{O}_3\right)}_2$ .

• A. Bromoaquotetraaminecobalt(III) nitrate
• B. Bromoaquotetraaminocobalt(III) nitrate
• C. Bromoaquatetraaminecobalt(III) nitrate
• D. Tetraammineaquabromocobalt(III) nitrate

Answer 1

Answer: (D)

Tetraammineaquabromocobalt(III) nitrate

The correct I.U.P.A.C. name for $\left[Co{\left(N{H}_3\right)}_4\left(H_{2}O\right)Br\right]{\left(N{O}_3\right)}_2$ complex is tetraammineaquabromocobalt(III) nitrate.

In this complex, ammine and water (aqua) are neutral ligands and, $Br$ and $N{O}_3$ has -1 charge.

The oxidation state of cobalt in this complex will be +3 so word 'cobalt' is used.

Oxidation state is written in roman letters within the brackets. Nitrate ions are present outside the sphere, so they will be named after naming the complex.