Coordination Compounds — Page 7 | NEET Chemistry

Q61

Which of the following will give a pair of enantiomorphs? (en = NH 2 CH 2 CH 2 NH 2 )

A [Cr(NH 3 ) 6 ][Co(CN) 6 ]

B [Co(en) 2 Cl 2 ]Cl

C [Pt(NH 3 ) 4 ][PtCl 6 ]

D [Co(NH 3 ) 4 Cl 2 ]NO 2

Correct Answer

Option B

Solution

Either a pair of crystals, molecules or compounds that are mirror images of each other but are not identical, and that rotate the plane of polarised light equally, but in opposite directions are called as enantiomorphs.

Q62

[Cr(H 2 O) 6 ]Cl 3 (At. no. of Cr = 24) has a magnetic momen of 3.83 B.M. The correct distribution of 3d electrons in the chromium of the complex is

A

3d_{x\,y}^1,\,3d_{y\,z}^1,\,3d_{z^2}^{1}

B

3d_{\left( {x^2 - y^2} \right)}^1,\,3d_{z^2}^1,\,3d_{xz}^1

C

3d_{x\,y}^1,\,\,3d_{\left( {x^2 - y^2} \right)}^1,\,3d_{y\,z}^1

D

3d_{x\,y}^1,\,3d_{y\,z}^1,\,3d_{x\,z}^1

Correct Answer

Option D

Solution

3.83 =

\sqrt {n\left( {n + 2} \right)}

$\Rightarrow$ n = 3 Thus, number of unpaired electrons in d-orbitals subshells of chromium (Cr = 24) = 3 $\therefore$ Configuration of Cr = 1s 2 2s 2 2p 6 3s 2 3p 6 3d 3 In 3d 3 the distribution of electrons

3d_{x\,y}^1,\,3d_{y\,z}^1,\,3d_{x\,z}^1

,

3d_{{x^2} - {y^2}}^0,3d_{{z^2}}^0

Q63

[Co(NH 3 ) 4 (NO 2 ) 2 ]Cl exhibits

A linkage isomerism, geometrical isomerism and optical isomerism

B linkage isomerism, ionization isomerism and optical isomerism

C linkage isomerism, ionization isomerism and geometrical isomerism

D ionization isomerism, geometrical isomerism and oprical isomerism.

Correct Answer

Option C

Solution

Ionization isomerism arises when the coordination compounds give different ions in solution.

Co(NH 3 ) 4 (NO 2 ) 2 ]Cl ⇌ Co(NH 3 ) 4 (NO 2 ) 2 ] + + Cl - Co(NH 3 ) 4 (NO 2 ) 2 ]Cl and Co(NH 3 ) 4 (ONO) 2 ]Cl are linkage isomers as NO 2 – is linked through N or through O.

Octahedral complexes of the type MA 4 B 2 exhibit geometrical isomerism.

Q64

Which one of the following is expected to exhibit optical isomerism? (en = ethylenediamine)

A cis -[Pt(NH 3 ) 2 Cl 2 ]

B trans -[Pt(NH 3 ) 2 Cl 2 ]

C cis -[Co(en) 2 Cl 2 ] +

D trans -[Co(en) 2 Cl 2 ] +

Correct Answer

Option C

Solution

cis -[Co(en) 2 Cl 2 ] + show optical isomerism because it forms a non-superimposable mirror image.

While trans-form contains plain of symmetry thus optically inactive.

Q65

Which one of the following is an inner orbital complex as well as diamagnetic in behaviour?

A [Zn(NH 3 ) 6 ] 2+

B [Cr(NH 3 ) 6 ] 3+

C [Co(NH 3 ) 6 ] 3+

D [Ni(NH 3 ) 6 ] 2+

Correct Answer

Option C

Solution

In [Co(NH 3 ) 6 ] 3+ Co +3 = [ 18 Ar] 3d 6 4s 0 [Co(NH 3 ) 6 ] 3+ is an inner orbital complex as well as diamagnetic in behaviour (due to absence of unpaired electrons).

Q66

Which of the following coordination compounds would exhibit optical isomerism?

A Pentaamminenitrocobalt (III) iodide

B Diamminedichloroplatinum (II)

C trans -Dicyanobis (ethyleneddiamine) chromium (III) chloride

D tris -(Ethylenediamine) cobalt (III) bromide.

Correct Answer

Option D

Solution

tris -(Ethylenediamine) cobalt (III) bromide [Co(en)3 ]Br 3 exhibits optical isomerism.

Q67

Considering H 2 O as a weak field ligand, the number of unpaired electrons in [Mn(H 2 O) 6 ] 2+ will be (atomic number of Mn = 25)

A three

B five

C two

D four

Correct Answer

Option B

Solution

In [Mn(H 2 O) 6 ] 2+ Mn +2 = [Ar] 3d 5 4s 0 In presence of weak field ligand H 2 O, there will be no pairing of electrons.

So it will form a high spin complex, i.e. the number of unpaired electrons = 5.

Q68

CN

-

is a strong field ligand. This is due to the fact that

A it carries negative charge

B it is a pseudohalide

C it can accept electrons from metal species

D it forms high spin complexes with metal species.

Correct Answer

Option B

Solution

CN – is a pseudohalide, i.e., it is a stronger coordinating ligand with the ability to form $\sigma$ and $\pi$ -bonds.

Q69

In an octahedral structure, the pair of

d

orbitals involved in d 2 sp 3 hybridisation is

A d x 2

-

y 2 , d z 2

B d xz , d x 2

-

y 2

C d z 2 , d xz

D d xy , d yz

Correct Answer

Option A

Solution

In the formation of d 2 sp 3 hybrid orbitals, two (n – 1)d orbitals of e g set [i.e. (n – 1)d z 2 and (n – 1)d x 2 – y 2 orbitals)], one ns and three np (np x , np y and np z ) orbitals combine together and form six d 2 sp 3 hybrid orbitals.

Q70

Which of the following does not have a metal carbon bond?

A Al(OC 2 H 5 ) 3

B C 2 H 5 MgBr

C K[Pt (C 2 H 4 )Cl 3 ]

D Ni(CO) 4

Correct Answer

Option A

Solution

Al(OC 2 H 5 ) 3 does not have metal-carbon bond. Its structure is