Cobalt(II) tetrachloro ion [CoCl4]2- Tetrachlorocobolt(II) ion 2 Reactions utilise: Tetrachlorocobolt(II) ion 3 Reactions form: Tetrachlorocobolt(II) ion Cl 4 Co 1   Charge = -2   Real ion. Gram formula weight (molecular mass) = 200.74 The tetrachlorocobolt(II) ion is tetrahedral and is coloured blue. Tetrachlorocobolt(II) ion is defined with respect to the entities below: The entities below are defined with respect to: Tetrachlorocobolt(II) ion Complex (AS/A2 generic) Real complex ion (generic) Type 23 Lewis acid/base complex (generic) VSEPR geometry = AX4 (generic) chemical compound molecule metal molecular science reaction mechanism ionic material acid base geometry reactivity synthesis science knowledge chemistry Lewis