Question

The IUPAC name of \([Co(en)_3]_2(SO_4)_3\) is

• A. tris(ethane-1,2-diamine)cobalt(III) sulphate
• B. bis(ethane-1,2-diamine)cobalt(III) sulphate
• C. bis(ethane-1,2-diamine)cobalt(II) sulphate
• D. tris(ethane-1,2-diamine)cobaltate(II) sulphate
• E. tris(ethylene-1,2-diamine)cobalt(III) sulphate

Hint:

"en" is the abbreviation for ethylenediamine, whose IUPAC name is ethane-1,2-diamine.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Naming coordination compounds: Ligands in alphabetical order, metal name, oxidation state in Roman numerals, then counter ion.

Step 2: Detailed Explanation:
Complex ion: \([Co(en)_3]^{3+}\).
- Ligand: en = ethane-1,2-diamine (neutral, bidentate).
- Three ligands → tris(ethane-1,2-diamine).
- Metal: cobalt. Oxidation state: en is neutral, SO\(_4^{2-}\) charge = -3 overall. Let Co = x, then 2x + 3(-2) = 0 ⇒ 2x = 6 ⇒ x = +3.
- Counter ion: sulphate.
Name: tris(ethane-1,2-diamine)cobalt(III) sulphate.

Step 3: Final Answer:
The correct IUPAC name is tris(ethane-1,2-diamine)cobalt(III) sulphate.