Oxidation number of the metal ion in the compound `[CO(NH_(3))_(5)Cl]Cl_(2)` is `+3`. Calculate the oxidation number of the complex ion. 

Explanation

Chlorine present outside the complex coordination sphere are chloride ions.
Since there are two `Cl^(-)` ions outside, the oxidation number of complex ion is +2.
The ion is given as `[Co(NH_(3))_(5)Cl]^(2+)`.