Coordination Compounds — Page 2 | NEET Chemistry

Q11

Ethylene diaminetetraacetate (EDTA) ion is :

A Tridentate ligand with three N donor atoms

B hexadentate ligand with four O and two N donor atoms

C Unidentate ligand

D Bidentate ligand with two N donor atoms

Correct Answer

Option B

Solution

Ethylene diaminetetraacetate (EDTA) ion is a hexadented ligand having four donor oxygen atoms and two donor nitrogen atoms

Q12

The calculated spin only magnetic moment of Cr 2+ ion is?

A 4.90 BM

B 5.92 BM

C 2.84 BM

D 3.87 BM

Correct Answer

Option A

Solution

Electronic configuration of

Cr:[Ar]3{d^5}4{s^1}

Electronic configuration of

C{r^{2 + }}

:[Ar]3d 4 No. of unpaired electrons = 4 Spin only magnetic moment =

\sqrt {n(n + 2)}

n = number of unpaired e $-$ Spin only magnetic moment =

\sqrt {4(4 + 2)}

=

\sqrt {24}

BM = 4.9 BM

Q13

Which of the following is the correct order of increasing field strength of ligands to form coordination compounds?

A SCN

-

< F

-

< CN

-

< C 2 O 4 2-

B F

-

< SCN

-

< C 2 O 4 2- < CN

-

C CN

-

< C 2 O 4 2- SCN

-

< F

-

D SCN

-

< F

-

< C 2 O 4 2- < CN

-

Correct Answer

Option D

Solution

Spectrochemical series (as given in NCERT) :

{L^ - } < B{r^ - } < SC{N^ - } < C{l^ - } < {S^{ - 2}} < {F^ - } < O{H^ - } < {C_2}{O_4}^{2 - } < {H_2}O < NC{S^ - } < EDT{A^{4 - }} < N{H_3} < en < C{N^ - } < CO

Q14

What is the correct electronic configuration of the central atom in K 4 [Fe(CN) 6 ] based on crystal field theory?

A

t_{2g}^4e_g^2

B

t_{2g}^6e_g^0

C

{e^3}t_2^3

D

{e^4}t_2^2

Correct Answer

Option B

Solution

Fe : [Ar]3d 6 4s 2 Fe 2+ : 3d 6

Q15

Iron carbonyl, Fe(CO) 5 is

A tetranuclear

B mononuclear

C trinuclear

D dinuclear

Correct Answer

Option B

Solution

Based on the number of metal atoms present in a complex, they are classified into mononuclear, dinuclear, trinuclear and so on. e.g. : Fe(CO) 5 : mononuclear Co 2 (CO) 8 : dinuclear Fe 3 (CO) 12 : trinuclear

Q16

The geometry and magnetic behaviour of the complex [Ni(CO) 4 ] are

A square planar geometry and diamagnetic

B tetrahedral geometry and diamagnetic

C square planar geometry and paramagnetic

D tetrahedral geometry and paramagnetic.

Correct Answer

Option B

Solution

Ni(28) : [Ar]3d 8 4s 2 CO is a strong field ligand, so unpaired electrons get paired.

Hence, configuration would be: For, four ‘CO’-ligands hybridisation would be sp3 and thus the complex would be diamagnetic and of tetrahedral geometry.

Q17

The type of isomerism shown by the complex [CoCl 2 (en) 2 ] is

A geometrical isomerism

B coordination isomerism

C ionization isomerism

D linkage isomerism.

Correct Answer

Option A

Solution

[CoCl 2 (en) 2 ] shows geometrical isomerism and exist in cis and trans form.

Q18

An example of a sigma bonded organometallic compound is

A Grignard's reagent

B ferrocene

C cobaltocene

D ruthenocene.

Correct Answer

Option A

Solution

Grignard's reagent is an organometallic compound in which carbon atom is bonded to metal ion with sigma bond while in ruthenocene, ferrocene and cobaltocene are the organo metallic compounds in which carbon atom is attached to metal ion thorough $\pi$ -bonding.

Q19

Correct increasing order for the wavelengths of absorption in the visible region for the complexes of Co 3+ is

A [Co(H 2 O) 6 ] 3+ , [Co(en) 3 ] 3+ , [Co(NH 3 ) 6 ] 3+

B [Co(H 2 O) 6 ] 3+ , [Co(NH 3 ) 6 ] 3+ , [Co(en) 3 ] 3+

C [Co(NH 3 ) 6 ] 3+ , [Co(en) 3 ] 3+ , [Co(H 2 O) 6 ] 3+

D [Co(en) 3 ] 3+ , [Co(NH 3 ) 6 ] 3+ , [Co(H 2 O) 6 ] 3+

Correct Answer

Option D

Solution

Increasing order of wavelength of absorption is

\Delta

0 = en > NH 3 > H 2

\Delta

0 = E =

{{hc} \over \lambda }

Thus, increasing order of wavelength of absorption is: [Co(en) 3 ] 3+ $<$ [Co(NH 3 ) 6 ] 3+ $<$ [Co(H 2 O) 6 ] 3+

Q20

The correct order of the stoichiometries of AgCl formed when AgNO 3 in excess is treated with the complexes : CoCl 3 .6NH 3 , CoCl 3 .5NH 3 , CoCl 3 .4NH 3 respectively is

A 3AgCl, 1AgCl. 2AgCl

B 3AgCl, 2AgCl, 1AgCl

C 2AgCl, 3AgCl, 2AgCl

D 1AgCl, 3AgCl, 2AgCl

Correct Answer

Option B

Solution

[Co(NH 3 ) 6 ]Cl 3 + 3AgNO 3 $\to$ 3AgCl $\downarrow$ + [Co(NH 3 ) 6 ](NO 3 ) 3 [Co(NH 3 ) 5 Cl]Cl 2 + 2AgNO 3 $\to$ 2AgCl $\downarrow$ + [Co(NH 3 ) 5 Cl](NO 3 ) 2 [Co(NH 3 ) 4 Cl 2 ]Cl + AgNO 3 $\to$ AgCl $\downarrow$ + [Co(NH 3 ) 4 Cl 2 ]NO 3