Question

The hypothetical complex chloro-diaamminecobalt(III) chloride can be represented as:

• A. \([\mathrm{CoCl(NH_3)_2(H_2O)_2}]Cl_2\)
• B. \([\mathrm{Co(NH_3)_3(H_2O)Cl_3}]\)
• C. \([\mathrm{Co(NH_3)_4(H_2O)_2Cl}]\)
• D. [Co(NH₃)₃(H₂O)₃]Cl₃

Hint:

In coordination compounds: • Ligands named first are inside the bracket • Oxidation state helps determine counter ions

Answer 1

The Correct Option is A

Step 1: Name analysis: • chloro ⟹ one Cl⁻ inside coordination sphere • diaammine ⟹ two NH₃ ligands • cobalt(III) ⟹ oxidation state +3
Step 2: Remaining ligands are water molecules to complete coordination number 6.
Step 3: Charge balance gives two chloride ions outside the coordination sphere.