Consider the following empirical formulas of octahedral complexes: CoCl ₃ 6 NH ₃ , NiCl ₂ 6 H ₂ O and CrCl ₃ 4 NH ₃ . One mole of the complex which is diamagnetic in nature is treated with an excess of aqueous AgNO ₃ solution. The number of moles of AgCl precipitated is ________.

Step-by-step solution

First, we determine the magnetic nature of the central metal ion in each octahedral complex. For CoCl ₃ 6 NH ₃ , the central metal is Co ³⁺ . The electronic configuration of Co ³⁺ is 3 d ^6 . Since NH ₃ acts as a strong field ligand for Co ³⁺ , the electrons pair up completely in the t_ 2g orbitals ( t_ 2g ^6 e_g^0 ). Thus, there are no unpaired electrons ( n=0 ), making it diamagnetic. For NiCl ₂ 6 H ₂ O , the central metal is Ni ²⁺ ( 3 d ^8 ). In an octahedral field, it has 2 unpaired electrons ( t_ 2g ^6 e_g^2 )