CBSE Class 12-science Answered

• K₄ [ Mn(CN)₆ ] is a coordination compound.
• The potassium ion is the cation and the complex ion is the anion.
• As there are 4 K⁺ binding with a complex ion, the charge on the complex ion must be - 4.
• As each ligand carries –1 charge, the oxidation number of Mn must be +2.
• What is written in the [ ]  is known as the coordination complex.eg [ Mn (CN)₆ ]
• The coordination complexes are made of a central metal ,[Mn] +(Ligands)] ;(CN) in this case.
• Ligands are simple atoms or groups of atoms that donate electrons.

• What is written outside[ ] , in this case K_4, is the primary valency / ionisable valency of the metal atom[within the complex].
• Central metal is Mn here. Let the  oxidation state of Mn ,the central metal be  x 

K₄ [ Mn(CN)₆ ]

(+4)  + x   (-6)  = 0  

• Thus x , the Oxidation state of the central metal atom Mn  is II which written at the end of the name.
• The name of central metal should end with “ate”. Here “manganate (II)”
• The ligands should be given prefix as hexa as there are 6 ligands.
• Hence the IUPAC name is potassium hexacyanomanganate(II)