VITEEE 2010 Paper

The correct formula of the given complex is tetraamine aqua chlorocobalt (III) chloride is [CoCl(H2O)(NH3)4]Cl2, because in it the oxidation number of Co is +3. While in rest other options O.No. of Co is +2 [CoCl(H2O)(NH3)4]Cl2
⇒x+(−1)+0+(0×4)+(−1)2=0
⇒x−3=0⇒x=+3