Target Exam

CUET

Subject

Chemistry

Chapter

Inorganic: Coordination Compounds

Question:

Write the IUPAC name for the coordination compound:

$[Cr(NH_3)_3(H_2O)_3]Cl_3$

Options:

triamminetriaquachromium (III) chloride

triaquatriamminechromium (III) chloride

tris(amminetriaqua) chromium (III) chloride

triammine-tris(aqua) chromium (III) chloride

Correct Answer:

triamminetriaquachromium (III) chloride

Explanation:

The correct answer is Option (1) → triamminetriaquachromium (III) chloride

1. Ligands: ''ammine'' $(NH_3)$ and ''aqua'' $(H_2O)$. Both are neutral.

2. Count & Alphabetize: 3 ammine, 3 aqua. ''ammine'' comes before ''aqua''. ⇒ triammine, triaqua.

3. Metal: Chromium (Cr).

4. Oxidation State: $\text{NH}_3(0)+\text{H}_2\text{O}(0)+\text{Cr}(x)=+3$ (due to $\text{3Cl}^{-}$ counterions) ⇒ x=+3 (Chromium(III)).

5. Counter-ion: Chloride.

Final Name: triammine-triaqua-chromium(III) chloride.