Question

Which statement regarding $Cr(N{H}_3{)}_6{]}^{3+}$ is incorrect ?

• A. It has octahedral geometry
• B. It has $d^{2}s{p}^3$ hybridisation
• C. It is diamagnetic
• D. It is low spin complex

Answer 1

The correct option is C It is diamagnetic

$C{r}^{3+}$ has electronic configuration of $\left[Ar\right]d^3.$ $C{r}^{3+}$hybridizes six empty orbitals, two 3d, one 4s and three 4p orbitals, to form six $d^{2}s{p}^3$ hybridised orbitals. which are occupied by six electrons pair from six $N{H}_3$ molecules The three unpaired 3d electrons making it occupy the three d-orbitals and hence are paramagnetic
Since the three electrons will occuy the available 3 d-orbitals as per Pauli"s exclusion principle they will be unpaired and high spin complex. Thus option (c) is correct