Question

One mole of a yellow coloured complex CoCl\(_3\cdot\)6NH\(_3\) gave three moles of AgCl on reaction with an excess of AgNO\(_3\). The conductivity of the solution of the complex is due to:

• A. 1 ion mol\(^{-1}\)
• B. 2 ions mol\(^{-1}\)
• C. 3 ions mol\(^{-1}\)
• D.

Hint:

For ionic complexes, the total number of ions in solution determines conductivity. Count cations + anions after dissociation.

Answer 1

The Correct Option is D

Step 1: Nature of the complex.
[Co(NH₃)₆]Cl₃ dissociates into the [Co(NH₃)₆]³⁺ cation and three chloride anions in solution.

Step 2: Precipitation with AgNO₃.
All three Cl⁻ ions react with Ag⁺ to yield 3 AgCl, confirming three free anions. Total ions = 1 cation + 3 anions = 4 ions.

Step 3: Conductivity basis.
Molar conductivity correlates with the total number of ions furnished per formula unit.

Step 4: Conclusion.
The complex produces 4 ions mol⁻¹ in solution.