Which of the following complex compound(s) is/are paramagnetic and low spin?

(I) ${\mathrm{K}}_3\left[\mathrm{Fe}(\mathrm{CN}{)}_6\right]$                       

(II) ${\left[\mathrm{Ni}(\mathrm{CO}{)}_4\right]}^0$

(III) ${\left[\mathrm{Cr}({\mathrm{NH}}_3{)}_6\right]}^{3+}$                       

(IV) ${\left[\mathrm{Mn}(\mathrm{CN}{)}_6\right]}^{4-}$

Choose the correct code :

(1) I only       (2) II and III        (3) I and IV       (4) IV only 

Among the following pairs of complexes , in which case the ${∆}_0$ value is higher fir the first one ?

(1) ${\left[\mathrm{Co}({\mathrm{NH}}_3{)}_6\right]}^{3+} \mathrm{and} {\left[\mathrm{Co}(\mathrm{CN}{)}_6\right]}^{3-}$         

(2) ${\left[{\mathrm{CoF}}_6\right]}^{3-} \mathrm{and} {\left[\mathrm{Co}({\mathrm{NH}}_3{)}_6\right]}^{3+}$

(3) ${\left[\mathrm{Co}({\mathrm{H}}_2\mathrm{O}{)}_6\right]}^{2+} \mathrm{and} {\left[\mathrm{Co}({\mathrm{H}}_2\mathrm{o}{)}_6\right]}^{3+}$         

(4) ${\left[\mathrm{Rh}({\mathrm{H}}_2\mathrm{O}{)}_6\right]}^{3+} \mathrm{and} {\left[\mathrm{Co}({\mathrm{H}}_2\mathrm{O}{)}_6\right]}^{3+}$

Dimethyl glyoxime forms a square planar complex with ${\mathrm{Ni}}^{2+}$. The complex should be:

(1) diamagnetic     

(2) paramagnetic having 1 unpaired electron 

(3) paramagnetic having 2 unpaired electron 

(4) ferromagnetic

What is the magnetic moment (spin only) and hybridisation of the brown ring complex $\left[\mathrm{Fe}({\mathrm{H}}_2\mathrm{O}{)}_5\mathrm{NO}\right]{\mathrm{SO}}_4$ ?

(1) $\sqrt{3} \mathrm{BM}, {\mathrm{sp}}^3{\mathrm{d}}^2$                     

(2) $\sqrt{3} \mathrm{BM}, {\mathrm{d}}^2{\mathrm{sp}}^3$

(3) $\sqrt{15} \mathrm{BM}, {\mathrm{sp}}^3{\mathrm{d}}^2$                   

(4) $\sqrt{15} \mathrm{BM}, {\mathrm{d}}^2{\mathrm{sp}}^3$

Choose incorrect stability order :

(1) ${\left[\mathrm{Cu}({\mathrm{NH}}_3{)}_4\right]}^{2+}<{\left[\mathrm{Cu}(\mathrm{en}{)}_2\right]}^{2+}<{\left[\mathrm{Cu}\left(\mathrm{trien}\right)\right]}^{2+}$

(2) ${\left[\mathrm{Fe}({\mathrm{H}}_2\mathrm{O}{)}_6\right]}^{3+}<{\left[\mathrm{Fe}({\mathrm{NO}}_2{)}_6\right]}^{3-}<{\left[\mathrm{Fe}({\mathrm{NH}}_3{)}_6\right]}^{3+}$

(3) ${\left[\mathrm{Co}({\mathrm{H}}_2\mathrm{O}{)}_6\right]}^{3+}<{\left[\mathrm{Rh}({\mathrm{H}}_2\mathrm{O}{)}_6\right]}^{3+}<{\left[\mathrm{Ir}({\mathrm{H}}_2\mathrm{O}{)}_6\right]}^{3+}$

(4) ${\left[\mathrm{Cr}({\mathrm{NH}}_3{)}_6\right]}^{1+}<{\left[\mathrm{Cr}({\mathrm{NH}}_3{)}_6\right]}^{2+}<{\left[\mathrm{Cr}({\mathrm{NH}}_3{)}_6\right]}^{3+}$

Aqueous solution of Ni²⁺ contains [Ni(H₂O)₆]²⁺ and its magnetic moment is 2.83 BM. When ammonia is added in it, the magnetic moment of solution:

1. Will remain the same.

2. Will increase from 2.83 BM.

3. Will decrease from 2.83 BM.

4. Cannot be predicted theoretically.

Which of the following is true about the complex $\left[{\mathrm{PtCl}}_2\right({\mathrm{H}}_2\mathrm{O}\left)\right({\mathrm{NH}}_3\left)\right]$ ?

(1) It exhibits geometrical isomerism

(2) It is a paramagnetic complex

(3) Its geometry is a tetrahedron 

(4) Platinum is ${\mathrm{sp}}^3$ hybridized 

Complex compound $\left[\mathrm{Cr}\right(\mathrm{NCS}\left)\right({\mathrm{NH}}_3{)}_5\left]\right[{\mathrm{ZnCl}}_4]$ will be:

(1) colourless and diamagnetic

(2) green coloured and diamagnetic

(3) green coloured and shows coordination isomerism

(4) diamagnetic and shows linkage isomerism

An aqueous solution of titanium chloride, when subjected to magnetic measurement, measured to zero magnetic moment. Assuming the octahedral complex in aqueous solution, the formula of the complex is :

(a) $\left[\mathrm{Ti}\right({\mathrm{H}}_2\mathrm{O}{)}_6]{\mathrm{Cl}}_2$                            (b) $\left[\mathrm{Ti}\right({\mathrm{H}}_2\mathrm{O}{)}_6]{\mathrm{Cl}}_4$

(c) $\left[{\mathrm{TiCl}}_3\right({\mathrm{H}}_2\mathrm{O}{)}_3]$                             (d) $\left[{\mathrm{TiCl}}_2\right({\mathrm{H}}_2\mathrm{O}{)}_4]$

Which of the following pairs of complexes are isomeric with each other but their aqueous solutions exhibit different molar conductivities?

(a) $\left[{\mathrm{PtCl}}_2\right({\mathrm{NH}}_3{)}_4]{\mathrm{Br}}_2 \mathrm{and} [{\mathrm{PtBr}}_2\left({\mathrm{NH}}_3{)}_4\right]{\mathrm{Cl}}_2$ 

(b) $\left[{\mathrm{CoCl}}_2\right({\mathrm{NH}}_3{)}_4]{\mathrm{NO}}_2 \mathrm{and} [\mathrm{CoCl}\left({\mathrm{NO}}_2\right)\left({\mathrm{NH}}_3{)}_4\right]\mathrm{Cl}$

(c) $\left[\mathrm{Co}\right({\mathrm{NO}}_2\left)\right({\mathrm{NH}}_3{)}_5]{\mathrm{Cl}}_2 \mathrm{and} [\mathrm{Co}\left(\mathrm{ONO}\right)\left({\mathrm{NH}}_3{)}_4\right]{\mathrm{Cl}}_2$

(d) $\left[\mathrm{CoBr}\right({\mathrm{NH}}_3{)}_5]{\mathrm{SO}}_4 \mathrm{and} [\mathrm{Co}\left({\mathrm{SO}}_4\right)\left({\mathrm{NH}}_3{)}_5\right]\mathrm{Br}$