Question

A co-ordination complex compound of cobalt has
the molecular formula containing five ammonia
molecules, one nitro group and two chlorine
atoms for one cobalt atom. One mole of this
compound produces three mole ions in an
aqueous solution. On reacting this solution with
excess of AgNO₃ solution, we get two moles of
AgCl precipitate. The ionic formula for this
complex would be
(a) [Co(NH₃)₄ (NO₂) Cl] [(NH₃ Cl]
(b) [Co (NH₃)₅ Cl] [Cl (NO₂)]
(c) [Co (NH₃)₅ (NO₂)] Cl₂
(d) [Co (NH₃)₅] [(NO₂)₂Cl₂]

Answer 1

Answer:

(d) [Co (NH₃)₅] [(NO₂)₂Cl₂]

Answer 2

(c) [Co (NH₃)₅ (NO₂)] Cl₂

Explanation:

From the given information, we know that on treating with AgNO3 solution, two moles of AgCl precipitate is formed. This implies that both the chloride ions are present outside the coordination sphere.

So the possible complex that give 3 moles ions in aqueous solution is [Co (NH₃)₅ (NO₂)] Cl₂ because it will give 2 chlorine atoms on ionisation.

Option C is the answer.