Answer:
[Co(NH₃)₄(H₂O)₂]³⁺: coordination number = 6.
[Cr(EDTA)]⁻: coordination number = 6.
[Pt(NH₃)₄]²⁺: coordination number = 4.
Na[Au(Cl)₂]: coordination number = 2.
Explanation:
In this complex, Co is bonded with 4 molecules of NH₃ (with 4 coordinate bonds, one bond for each molecule) and 2 molecules of H₂O (with 2 coordinate bonds, one bond for each molecule) forming the complex with 6 coordinate bonds.
∴ coordination number = 6.
In this complex, Cr is bonded with 1 molecules of EDTA (with 6 coordinate bonds, 4 O atoms and 2 N atoms in EDTA molecule).
∴ coordination number = 6.
In this complex, Pt is bonded with 4 molecules of NH₃ (with 4 coordinate bonds, one bond for each molecule).
coordination number = 4.
In this complex, Au is bonded with 2 atoms of Cl (with 2 coordinate bonds, one bond for each atom).
coordination number = 2.
