Write the formula of a coordination compound made of two complex ions: one a complex of v(iii) with two ethylenediamine molecules and two cl− ions as ligands and the other a complex of ni(ii) having a coordination number of 4 with cl− ions as ligands.

The answer is:  " [V₍en₎₂Cl₂]₂ [NiCl₄] " .


Explanation:

 
Note that:   [V³⁺ ₍en₎₂ (Cl⁻)²] is a "+1" charged cation;  and that:+1 ion 

[Ni²⁺ (Cl⁻)₄ is a "-2" charged anion; 

As such:  the chemical formula for the compound is written as:


                             →   "[V₍en₎₂Cl₂]₂ [NiCl₄]  ; 

 The answer is:  " [V₍en₎₂Cl₂]₂ [NiCl₄] " .