Question 14 of 34beginner🔧 ApplyShort Answer2 marks
Specify the oxidation numbers of the metals in the following coordination entities:
(i)
[Co(H2O)(CN)(en)2]2+
Answer
Oxidation number of Co = +3
(ii)
[CoBr2(en)2]+
Answer
Oxidation number of Co = +3
(iii)
[PtCl4]2-
Answer
Oxidation number of Pt = +2
(iv)
K3[Fe(CN)6]
Answer
Oxidation number of Fe = +3
(v)
[Cr(NH3)3Cl3]
Answer
Oxidation number of Cr = +3
Explanation
The oxidation number of the central atom is the charge it would carry if all ligands were removed along with their electron pairs. Neutral ligands (H₂O, NH₃, en) contribute zero charge, while anionic ligands contribute their respective negative charges (CN⁻ = -1, Br⁻ = -1, Cl⁻ = -1). The sum of oxidation number of metal and charges of ligands equals the charge on the coordination entity.