An aqueous solution of `CoCl_(3).6NH_(3)` is found to be a better conductor of electricity than an aqueous solution of `CoCl_(3).4NH_(3)` No ammonium ions are detected by addition of `H_(2) SO_(4)` to the solution of either of these compounds. Can you explain the difference in the conductivities of two solutions

Explanation

As no ammonium ions are detected in the solutions of these compounds, it indicates that ammonia molecules are in the first coordination sphere of the metal ion in both the cases. The compound `COCI_(3), 6NH_(3)` can therefore be formulated as `[CO(NH_(3))_(6)]Cl_(3)` which may give four ions per mole in solution as indicated by the conductivity of the solution. Since the solution of `CoCl_(3), 4NH_(3)` is less conducting than that of `CoCl_(3).6NH_(3)` it means it give less than four ions per mole in solution. It will be possible only if two of the chlorines are also present in the first coordination sphere and the compound has the formula`(Co(NH_(3))_(4)Cl_(2)]CI`.