Question

As per IUPAC nomenclature, the name of the complex $[Co(H_{2}O{)}_4(N{H}_3{)}_2]C{l}_3$ is

• A. tetraaquadiaminecobalt (III) chloride
• B. tetraaquadiamminecobalt (III) chloride
• C. diaminetetraaquacobalt (II) chloride
• D. diamminetetraaquacobalt (III) chloride
• E. Tetraaquadiaminecobalt (II) chloride

Answer 1

Answer: (D)

First of all, the compound has complex positive part " ${\left[Co{\left(H_{2}O\right)}_4{\left(N{H}_3\right)}_2\right]}^{3+}$ therefore, according to IUPAC conventions, positive part will be named first. Secondly, in writing name of complex, ligands are named first in alphabetical order, irrespective of its charge, hence "ammine" will be written prior to "aqua".