You are given the following two complex X and Y which are isomer of each other , X is Hg `[Co(SCN)_(4)]`. It is further given that 'spin only' magnetic moment of X is found to be 3.78 B.M. and that of Y is 1.73 B.M. Then which of the following is correct ?

Options

A. Anion of X will be tetrahedral and that of Y will be square planar
B. Anion of X will be square planar but that of Y will be tetrahedral
C. Both the anions will be tetrahedral
D. Both the anions will be square planar

Answer

A

Explanation

In Hg `[Co(SCN)_(4)](X),` the cobalt is in +2 oxidation state.
`mu=sqrt(n(N+2)),` So, 3.78 B.M.`=sqrt(n(n+2)) or n=3`

In Hg `[Co(NCS)_(4)]` (Y), the cobalt is in +2 oxidation state. Further'spin only ' magnetic moment of complex,
`Hg[Co(NCS)_(4)]` is 1.73 B.M. So, `mu=sqrt(n(n+2)), ` So, 1.73 B.M`=sqrt(n(N+2)) or n=1`
ltrbgt so, X is tetrahedral and Y is square planar.