The calculated magnetic moment value for the $Fe^{2+}$ ion in $BM$ is:

The compounds $[Cr(H_2O)_6]Cl_3$,$[Cr(H_2O)_5Cl]Cl_2 \cdot H_2O$ and $[Cr(H_2O)_4Cl_2]Cl \cdot 2H_2O$ exhibit:

Which type of isomerism is exhibited by the square planar complex shown in the image?

Identify the complex compound$(s)$ which is/are optically active and whose optical activity does not depend upon the orientation of the ligands around the metal cation:
$(i). [CoCl_3(NH_3)_3]$
$(ii). [Co(en)_3]Cl_3$
$(iii). [Co(C_2O_4)_2(NH_3)_2]^-$
$(iv). [CrCl_2(NH_3)_2(en)]^+$

The correct order of spin-only magnetic moment of the following complex ions is: (Given At. No. $Fe: 26, Co: 27$)

An aqueous solution of $[Ni(H_2O)_6]^{2+}$ contains $Ni^{2+}$ ions and has a magnetic moment of $2.83 \ BM$. What is the effect on the magnetic moment of the solution when ammonia is added?