Practice Start Test

Coordination Compounds

NEET Chemistry · 85 questions · Page 5 of 9 · Click an option or "Show Solution" to reveal answer

Q41
Red precipitate is obtained when ethanol solution of dimethylglyoxime is added to ammoniacal Ni(II). Which of the following statements is not true?
A Red complex has a square planar geometry.
B Complex has symmetrical H-bonding.
C Red complex has a tetrahedral geometry.
D Dimethylglyoxime functions as bidenate ligand.
Correct Answer
Option C
Solution

Ni +2 + 2Dmg– → [Ni(Dmg) 2 ] Dimethyl glyoxime act as bidentate ligand.

Q42
Low spin complex of d 6 -cation in an octahedral field will have the following energy
A −125Δo+P{{ - 12} \over 5}{\Delta _o} + P
B −125Δo+3P{{ - 12} \over 5}{\Delta _o} + 3P
C −25Δo+2P{{ - 2} \over 5}{\Delta _o} + 2P
D −25Δo+P{{ - 2} \over 5}{\Delta _o} + P
Correct Answer
Option B
Solution

For low spin d 6 complex electronic configuration =

t2g6eg0t_{2g}^6e_g^0

∴\therefore x = 6, y = 0, z = 3 C.F.S.E. = (– 0.4 × 6 + 0 × 0.6)

Δ\Delta

0 + 3P =

−125Δ0+3P- {{12} \over 5}{\Delta _0} + 3P
Q43
Which one of the following is an outer orbital complex and exhibits paramagnetic behaviour?
A [Ni(NH 3 ) 6 ] 2+
B [Zn(NH 3 ) 6 ] 2+
C [Cr(NH 3 ) 6 ] 3+
D [Co(NH 3 ) 6 ] 3+
Correct Answer
Option A
Solution

Those orbitals which utilizes 3d-orbitals for bonding and exhibit paramagnetic behaviour forms outer orbital complex.

Ni +2 = [Ar] 3d 8 4s 0 ∴\therefore It forms outer orbital complex. (b) [Zn(NH 3 ) 6 ] 2+ ⇒\Rightarrow outer orbital complex but diamagnetic (c) [Cr(NH 3 ) 6 ] 3+ ⇒\Rightarrow inner orbital complex but paramagnetic (d) [Co(NH 3 ) 6 ] 3+ ⇒\Rightarrow inner orbital complex but diamagnetic

Q44
Which of the following carbonyls will have the strongest C–O bond ?
A Cr (CO) 6
B Fe (CO) 5
C Mn (CO) 6 +
D V(CO) 6 -
Correct Answer
Option C
Solution

Due to positive oxidation state of Mn back donation in π* ABMO of CO is minimum therefore C–O bond is strongest.

Q45
Which of the following complex compounds will exhibit highest paramagnetic behaviour? (At. No. Ti = 22, Cr = 24, Co = 27, Zn = 30)
A [Cr (NH 3 ) 6 ] 3+
B [Co (NH 3 ) 6 ] 3+
C [Zn (NH 3 ) 6 ] 2+
D [Ti(NH 3 ) 6 ] 3+
Correct Answer
Option A
Solution

[Cr(NH 3 ) 6 ] +3 [Ar] 3d 3 4s 0 three unpaired electron are present in t 2g orbited

Q46
The d -electron configurations of Cr 2+ , Mn 2+ , Fe 2+ and Co 2+ are d 4 , d 5 , d 6 and d 7 respectively. Which one of the following will exhibit minimum paramagnetic behaviour? (At. Nos. Cr = 24, Mn = 25, Fe = 26, Co = 27)
A [Mn(H 2 O) 6 ] 2+
B [Fe(H 2 O) 6 ] 2+
C [Co(H 2 O) 6 ] 2+
D [Cr(H 2 O) 6 ] 2+
Correct Answer
Option C
Solution

[Mn(H 2 O) 6 ] 2+ : Mn 2+ = 3d 5 ∴\therefore Number of unpaired electron = 5 [Fe(H 2 O) 6 ] 2+ : Fe 2+ = 3d 6 ∴\therefore Number of unpaired electrons = 4 [Co(H 2 O) 6 ] 2+ : Co 2+ = 3d 7 ∴\therefore Number of unpaired electrons = 3 [Cr(H 2 O) 6 ] 2+ : Cr 2+ = 3d 4 Number of unpaired electrons = 4 Minimum paramagnetic behaviour is shown by [Co(H 2 O) 6 ] 2+ .

Q47
The complexes [Co(NH 3 ) 6 ] [Cr(CN) 6 ] and [Cr(NH 3 ) 6 ] [Co(CN) 6 ] are the examples of which type of isomerism?
A Linkage isomerism
B Ionization isomerism
C Coordination isomerism
D Geometrical isomerism
Correct Answer
Option C
Solution

Coordination isomerism arises from the interchange of ligands between cationic and anionic entities of different metal ions present in the complex.

[Co (NH 3 ) 6 ] [Cr(CN) 6 ] is an isomer of [Co(CN) 6 ] [Cr(NH 3 ) 6 ]

Q48
The complex, [Pt(Py)(NH 3 )BrCl] will have how many geometrical isomers ?
A 3
B 4
C 0
D 2
Correct Answer
Option A
Solution

Complexes of the type M ABCD may exist in three isomeric forms.

Similarly, [Pt(Py)(NH 3 )BrCl] may exist in three isomeric form in which M = Pt, A = Py, B = NH 3 , C = Br, D = Cl.

Q49
Which of the following complex compounds will exhibit highest paramagnetic behaviour?
A [Ti(NH 3 ) 6 ] 3+
B [Cr(NH 3 ) 6 ] 3+
C [Co(NH 3 ) 6 ] 3+
D [Zn(NH 3 ) 6 ] 2+
Correct Answer
Option B
Solution

Ti 3+ →\to [Ar] 3d 1 4s 0 (1 unpaired electron) Cr 3+ →\to [Ar] 3d 3 4s 0 (3 unpaired electrons) Co 3+ →\to [Ar] 3d 6 4s 0 (0 unpaired electrons because of pairing) Zn 2+ →\to [Ar] 3d 10 (no unpaired electrons) [Cr(NH 3 ) 6 ] 3+ exhibits highest paramagnetic behaviour as it contains 3 unpaired electrons.

Q50
Which of the following carbonyls will have the strongest C −- O bond?
A Mn(CO) 6 +
B Cr(CO) 6
C V(CO) 6 −-
D Fe(CO) 5
Correct Answer
Option A
Solution

As + ve charge on the central metal atom increases, the less readily the metal can donate electron density into the π\pi* orbitals of CO ligand to weaken the C – O bond.

Hence, the C – O bond would be strongest in Mn(CO) 6 + .

Ready for a full NEET mock test? Timed · full syllabus · instant results
Take a Mock Test →