According to werner primary valency of central atom in Pt(en)2(H2O)2Cl4 Complex is
5
3
6
4
Pt(en)2(H2O)2Cl4 For this,x+2(2x0)+2(0)+4(-1)=0; X=+4 , primary valency satisfied by negative ligands/ species i.e Cl- , so primary valency = 4