Question

Which of the following is correct about Tetraamminedithiocyanato-s cobalt(III) tris(oxalato)cobaltate (III)?

• A. Formula of complex is $\left[Co\right(SCN{)}_2\left(N{H}_3{)}_4\right]\left[Co\right(ox{)}_3]$
• B. It is a chelating complex and show linkage isomerism
• C. It show optical isomerism
• D. It show geometrical isomerism

Answer 1

Answer: (B), (C), (D)

The correct options are
B It is a chelating complex and show linkage isomerism
C It show optical isomerism
D It show geometrical isomerism

(A) The formula of the complex Tetraamminedithiocyanato-s cobalt(III) tris(oxalato)cobaltate (III) is $\left[C{o}^{III}\right(SCN{)}_2\left(N{H}_3{)}_4{]}_3\right[C{o}^{III}\left(ox{)}_3\right]$ and not $\left[Co\right(SCN{)}_2\left(N{H}_3{)}_4\right]\left[Co\right(ox{)}_3]$ because to balance the charge, three units of complex cation and one unit of complex anion are present in one formula unit.
Thus option A is incorrect.
(B) Linkage isomerism is possible as SCN ligand is ambidentate ligand and has two donor atoms N and S.
Thus option B is correct.
(C) The complex ion $\left[Co\right(ox{)}_3{]}^{3-}$ has elements of asymmetry and is optically active.
Thus option C is correct.
(D) The complex cation $\left[Co\right(SCN{)}_2(N{H}_3{)}_4{]}^{+1}$ shows geometrical isomerism.
Thus option D is correct.