Lesson eLearning

Write the correct IUPAC name for the complex .

medium 2 marks Class 12 · Chemistry · Coordination Compounds
Answer
tetraamminechloridochloridochromium(III) chloride monohydrate

The correct answer is tetraamminechloridochloridochromium(III) chloride monohydrate — Combine all parts: tetraamminechloridochloridochromium(III) chloride monohydrate.

Step-by-step solution

  1. Identify the central metal atom: Cr.
  2. Determine the oxidation state of Cr: Let x be oxidation state. 4(NH₃) are neutral, 2Cl⁻ give -2, overall complex charge is +1 (since one external Cl⁻ balances). So x - 2 = +1 ⇒ x = +3. Hence chromium(III).
  3. Arrange the ligands in alphabetical order ignoring prefixes: ammine (from NH₃) comes before chloro (from Cl⁻).
  4. Write the ligand names with appropriate multiplicative prefixes: tetraammine, dichloro (or chlorido twice). Since there are two chloride ligands inside the coordination sphere, use "dichloro" or "chlorido" twice. IUPAC prefers "chlorido".
  5. Combine the ligand part: tetraamminechloridochlorido.
  6. Add the metal name with oxidation state: chromium(III).
  7. Write the counter ion and water of crystallisation: chloride monohydrate.
  8. Combine all parts: tetraamminechloridochloridochromium(III) chloride monohydrate.
Common mistake: Forgetting to include the external chloride and water of crystallisation in the name.

Concept tested: Naming of coordination compounds (IUPAC)

Published · How this solution was prepared and checked

← All Coordination Compounds questions