Co - ordination Compounds MCQ Questions & Answers in Inorganic Chemistry | Chemistry

Non superimposable mirror images are called optical isomers and may be described as “chiral’. They are also called enantiomers and rotate plane polarised light in opposite directions.

$${K_3}\left[ {Fe{{\left( {CN} \right)}_6}} \right]$$   is potassium hexacyano ferrate (III).

$$Hg{I_2}\left( s \right) + 2{I^ - }\left( {aq} \right) \to {\left[ {Hg{I_4}} \right]^{2 - }}\left( {aq} \right)$$

In $${\left[ {Co{{\left( {N{H_3}} \right)}_6}} \right]^{3 + }},$$   oxidation state of $$Co = + 3$$   and its coordination number is six.
$$\eqalign{ & _{27}Co = 1{s^2},2{s^2}2{p^6},3{s^2}3{p^6}3{d^7},4{s^2} \cr & C{o^{3 + }} = 1{s^2},2{s^2}2{p^6},3{s^2}3{p^6}3{d^6} \cr} $$

$${\left[ {Co{{\left( {N{H_3}} \right)}_6}} \right]^{3 + }}$$   is an inner orbital complex as well as diamagnetic in behaviour ( due to absence of unpaired electrons ).
$${\left[ {Zn{{\left( {N{H_3}} \right)}_6}} \right]^{2 + }} \to s{p^3}{d^2}$$     hybridisation ( outer orbital complex and diamagnetic in nature ).
$${\left[ {Cr{{\left( {N{H_3}} \right)}_6}} \right]^{3 + }} \to {d^2}s{p^3}$$     hybridisation ( inner orbital complex and paramagnetic in nature ).

Shape of $${\left[ {Cu{{\left( {N{H_3}} \right)}_4}} \right]^{2 + }}$$   is square planar.

$$E.C.\,{\text{of}}\,C{r^{3 + }}\left( {3{d^3}} \right):$$    
For complex A $${\left[ {Cr{{\left( {{H_2}O} \right)}_2}} \right]^{3 + }}:$$

For complex B $${\left[ {Cr{{\left( {N{H_3}} \right)}_6}} \right]^{3 + }}:$$

Here, both the complexes $$\left( A \right)\,{\text{and}}\,\left( B \right)$$   are paramagnetic with $$3$$ unpaired electrons each. Also $$H2O$$  is a weak field ligand which causes lesser splitting than NH3 which is comparatively stronger field ligand. Hence, the $$\left( {D0} \right)$$  value of $$\left( A \right)\,{\text{and}}\,\left( B \right)$$   are calculated from the wavelengths of light absorbed and not from the wavelengths of light emitted.

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Due to some backbonding by sidewise overlapping of between $$d{\text{ - orbitals}}$$   of metal and $$p{\text{ - orbitals}}$$   of carbon, the $$Fe - C$$  bond in $$Fe{\left( {CO} \right)_5}$$  has both $$\sigma $$  and $$\pi $$  character.

The correct name is chlorobis ( ethylenediamine ) nitritocobalt (III).

As number of stable rings increases stability of complex compound also increases due to chelation effect.
Number of rings in $${\left[ {Ni{{\left( {en} \right)}_2}} \right]^{2 + }} = 2$$
Number of rings in $$\left[ {Ni{{\left( {dmg} \right)}_2}} \right] = 4$$