Chemistry Coordination Compounds

Stability constant are :

K₁ = 10⁴

K₂ = 1.58 * 10³

K₃ = 5 * 10²

K₄ = 10²

Overall stability constant K will be

K = K₁ * K₂ * K₃ * K₄

 = 7.9 * 10¹¹

Now, overall equilibrium constant for dissociation of [Cu (NH₃)₄]²⁺ is

$K\text{'}=\frac{1}{K}=\frac{1}{7.9*10^{11}}=0.126*10^{-11}$  

= 1.26 * 10^-12

So; x = 1 (Rounded off to the nearest integer)

Kindly consider the following figure

Statement – I True

Statement – II False

Dimethyl glyoxime is the bidentate anionic ligand.

$N{i}^{2+}+2DM{G}^{-}\to \underset{Redppt}{\left[Ni{\left(DMG\right)}_2\right]}$

I > III > IV > II

${\left[Fe{F}_6\right]}^{3-}\to F{e}^{3+}-3d^5-$ all are unpaired (n = 5)

${\left[Co{\left(N{H}_3\right)}_6\right]}^{3+}\to C{o}^{3+}-3d^6-$ all are paired (n = 0)

${\left[NiC{l}_4\right]}^{2-}\to N{i}^{2+}-3d^8\to \left(n=2\right)$

${\left[Cu{\left(N{H}_3\right)}_4\right]}^{2+}\to C{u}^{++}\to 3d^9\to \left(n=1\right)$

Spin only moment ;  = $\mu$ 3.87 BM

$\mu =\sqrt[]{n\left(n+2\right)}B.M$                

3.87 =    $\sqrt[]{n\left(n+2\right)}BM$

So, number of unpaired electrons; n = 3

ln ;

$C{r}^{3+}-4s^{0}3d^{3}n=3$

So; $M^{z+}$ cannot be V³⁺

$\left[Cu{\left(en\right)}_2{\left(SCN\right)}_2\right]$

More stable isomers = 3 (trans isomers)

NH₃ behaves as strong field ligand with Co²⁺ & Co³⁺

$\left[Co{\left(N{H}_3\right)}_6\right]C{l}_2$              

$C{o}^{2+}-4s^{0}3d^7$      

It has one unpaired electorn.

 $\left[Co{\left(N{H}_3\right)}_6\right]C{l}_3$

$C{o}^{3+}-4s^{0}3d^6$    

It has no unpaired electrons

So, total unpaired electrons in both compounds is 1.

(A) $N{i}^{2+}-4s^{0}3d^8$ - Paramagnetic & coloured

$M{n}^{7+}-4s^{0}3d^0$       - Diamagnetic & colourless

$H{g}^{2+}-6s^{0}4f^{14}5d^{10}$ - Diamagnetic & colourless

(B)  $C{u}^{+}-4s^{0}3d^{10}$    - Diamagnetic & colourless

$Z{n}^{2+}-4s^{0}4d^{10}$          - Diamagnetic & colourless

$M{n}^{4+}-4s^{0}3d^3$    - paramagnetic & coloured

(C)  $S{c}^{3+}-4s^{0}3d^0$

$\begin{array}{l}{V}^{5+}-4s^{0}3d^0\\ T{i}^{4+}-4s^{0}3d^0\end{array}$  

All are diamagnetic & colourless

(D)  $C{u}^{2+}-4s^{0}3d^9$  

$\begin{array}{l}C{r}^{3+}-4s^{0}3d^3\\ S{c}^{+}-4s^{1}3d^1\end{array}$

All are paramagnetic & coloured

All d- & f block paramagnetic cations are coloured also.

For Ni²⁺, crystal field CFSE magnitude shows the magnitude of absorbed light. Following are the energy absorbed order

  ${\left[NiC{l}_4\right]}^{2-}<{\left[Ni\left(H_{2}O\right)\right]}^{2+}<{\left[Ni{\left(CN\right)}_4\right]}^{2-}$

Hence order of colour of compounds are.

${\left[NiC{l}_4\right]}^{2-}>{\left[Ni{\left(H_{2}O\right)}_6\right]}^{2+}>{\left[Ni{\left(CN\right)}_4\right]}^{2-}$