CBSE Class 12 Chemistry Coordination Compounds MCQs Set B

Question. The correct order of the stoichiometries of AgCl formed when AgNO₃ in excess is treated with the complexes : CoCl₃.6NH₃, CoCl₃.5NH₃, CoCl₃.4NH₃ respectively is
(a) 3AgCl, 1AgCl, 2AgCl
(b) 3AgCl, 2AgCl, 1AgCl
(c) 2AgCl, 3AgCl, 2AgCl
(d) 1AgCl, 3AgCl, 2AgCl

Answer : B

Question. Shape of Fe(CO)₅ is
(a) octahedral
(b) square planar
(c) trigonal bipyramidal
(d) square pyramidal.

Answer : C

Question. In metal carbonyl having general formula M(CO)_x where M = metal, x = 4 and the metal is bonded to
(a) carbon and oxygen
(b) C O
(c) oxygen
(d) carbon.

Answer : D

Question. CuSO₄ when reacts with KCN forms CuCN, which is insoluble in water. It is soluble in excess of KCN, due to formation of the following complex
(a) K₂[Cu(CN)₄]
(b) K₃[Cu(CN)₄]
(c) CuCN₂
(d) Cu[KCu(CN)₄]

Answer : C

Question. Cobalt(III) chloride forms several octahedral complexes with ammonia. Which of the following will not give test for chloride ions with silver nitrate at 25°C?
(a) CoCl₃ · 5NH₃
(b) CoCl₃ · 6NH₃
(c) CoCl₃ · 3NH₃
(d) CoCl₃ · 4NH₃

Answer : C

Question. An excess of AgNO₃ is added to 100 mL of a 0.01 M solution of dichlorotetraaquachromium(III) chloride. The number of moles of AgCl precipitated would be
(a) 0.003
(b) 0.01
(c) 0.001
(d) 0.002

Answer : C

Question. Which of the following will exhibit maximum ionic conductivity?
(a) K₄[Fe(CN)₆]
(b) [Co(NH₃)6]Cl₃
(c) [Cu(NH₃)4]Cl₂
(d) [Ni(CO)₄]

Answer : A

Question. Which one of the following has a square planar geometry? (Atomic Number of Fe= 26, Co= 27, Ni= 28, Pt= 78)
(a) [CoCl₄ ]^2-
(b) [FeCl₄ ]^2- 
(c) [NiCl₄ ]^2-
(d) [PtCl₄ ]^2-

Answer : D

Question. Which of the following complex has zero magnetic moment (spin only)?
(a) [Ni(NH₃ )₆ ]Cl₂
(b) Na₃[FeF₆]
(c) [Cr(H₂O)₆]SO₄
(d) K₄[Fe(CN)₆]

Answer : D

Question. Among [Ni(CO)₄ ]^2- , [Ni(CN)⁴ ]^2- and [NiCl₄ ]^2- species, the hybridisation states of the Ni atom are, respectively (Atomic number of Ni= 28) 
(a) sp³, dsp², dsp²
(b) sp³, dsp²,sp³
(c) sp³, sp³, dsp²
(d) dsp², sp³, sp

Answer : B

Question. CN- is 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

Answer : B

Question. Considering H₂O as weak field ligand, the number of unpaired electrons in [Mn(H₂O)₆ ]²⁺ will be
(Atomic number of Mn = 25)
(a) three
(b) five
(c) two
(d) four

Answer : B

Question. In an octahedral structure, the pair of d-orbitals involved in d²sp ³ hybridisation is 
(a) d_{x² – y²} ,d_z²
(b) d_xz ,d_{x² – y²}
(c) d_z² ,d_xz 
(d) d_xy ,d_yz

Answer : C

Question. The geometry of Ni(CO)₄ and Ni(PPh₃)₂ Cl₂ are
(a) both square planar
(b) tetrahedral and square planar respectively
(c) both tetrahedral
(d) square planar and tetrahedral respectively

Answer : D

Question. Ammonia forms the complex ion [Cu(NH₃ )₄ ]²⁺ with copper ions in the alkaline solutions but not in acidic solutions. What is the reason for it ?
(a) In acidic solutions hydration protects copper ions
(b) In acidic solutions protons coordinate with ammonia molecules forming NH⁺₄ ions and NH₃ molecules are not available
(c) In alkaline solutions insoluble Cu(OH)₂ is precipitated which is soluble in excess of any alkali
(d) Copper hydroxide is an amphoteric substance

Answer : B

Question. Which of the following statements is not correct?
(a) The complexes [NiCl₄]^2- and [Ni(CN)₄]^2- differ in the state of hybridisation ofnickel
(b) The complexes [NiCl₄]^2- and [Ni(CN)₄]^2-– differ in the magnetic properties
(c) The complexes [NiCl₄]^2- and [Ni(CN)₄]^2- differ in geometry
(d) The complexes [NiCl₄]^2- and [Ni(CN)₄]^2-– differ in primary valencies of nickel

Answer : D

Question. In the silver plating of copper, K[Ag(CN)₂] is used instead of AgNO₃. The reason is
(a) a thin layer of Ag is formed on Cu
(b) more voltage is required
(c) Ag⁺ ions are completely removed from solution
(d) less availability of Ag⁺ ions, as Cu cannot displace Ag from [Ag(CN)₂]^– ion

Answer : D

Question. The complex, [Pt(py)(NH₃)BrCl] will have how many geometrical isomers?
(a) 3
(b) 4
(c) 0
(d) 2

Answer : A

Question. The existence of two different coloured complexes with the composition of [Co(NH₃)₄Cl₂]+ is due to
(a) linkage isomerism
(b) geometrical isomerism
(c) coordination isomerism
(d) ionization isomerism

Answer : B

Question.The sum of coordination number and oxidationnumber of the metal M in the complex [M(en)₂(C₂O₄)]Cl (where en is ethylenediamine) is
(a) 6
(b) 7
(c) 8
(d) 9

Answer : D

Question.The anion of acetylacetone (acac) forms Co(acac)₃ chelate with Co³⁺. The rings of the chelate are
(a) five membered
(b) four membered
(c) six membered
(d) three membered.

Answer : C

Question. Which of the following statements is true?
(a) Silicon exhibits 4 coordination number in its compound.
(b) Bond energy of F₂ is less than Cl₂.
(c) Mn(III) oxidation state is more stable than Mn(II) in aqueous state.
(d) Elements of 15^th gp shows only +3 and +5 oxidation states

Answer : B

Question. Coordination number of Ni in [Ni(C₂O₄)₃]⁴– is
(a) 3
(b) 6
(c) 4
(d) 2

Answer : B

Question. The coordination number and oxidation state of Cr in K₃[Cr(C₂O₄)³] are respectively
(a) 3 and + 3
(b) 3 and 0
(c) 6 and + 3
(d) 4 and + 2

Answer : C

Question. A coordination complex compound of cobalt has the molecular formula containing five ammonia molecules, one nitro group and two chlorine atoms for one cobalt atom. One mole of this compound produces three mole ions in an aqueous solution. On reacting this solution with excess of AgNO3 solution, we get two moles of AgCl precipitate. The ionic formula for this complex would be A
(a) [Co(NH₃)₅(NO₂)]Cl₂
(b) [Co(NH₃)₅Cl][Cl(NO₂)]
(c) [Co(NH₃)₄(NO₂)Cl][(NH₃)Cl]
(d) (Co(NH₃)₅][(NO₂)2Cl₂]

Answer : A

Question. The correct increasing order of trans-effect of thefollowing species is
(a) NH₃ > CN– > Br– > C6H₅–
(b) CN– > C6H5– > Br– > NH₃
(c) Br– > CN– > NH₃ > C₆H₅–
(d) CN– > Br– > C₆H₅– > NH₃

Answer : B

Question. 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.

Answer : B

Question. Correct increasing order for the wavelengths of absorption in the visible region for the complexes of Co³⁺ is
(a) [Co(H₂O)₆]³⁺, [Co(en)₃]³⁺, [Co(NH₃)₆]³⁺
(b) [Co(H₂O)₆]³⁺, [Co(NH₃)₆]³⁺, [Co(en)₃]³⁺
(c) [Co(NH₃)₆]³⁺, [Co(en)₃]³⁺, [Co(H₂O)₆]³⁺
(d) [Co(en)₃]³⁺, [Co(NH₃)₆]³⁺, [Co(H₂O)₆]³⁺

Answer : D

Question. Pick out the correct statement with respect to [Mn(CN)₆]^3–.
(a) It is sp³d² hybridised and tetrahedral.
(b) It is d²sp³ hybridised and octahedral.
(c) It is dsp² hybridised and square planar.
(d) It is sp³d² hybridised and octahedral.

Answer : B

Question. Jahn–Teller effect is not observed in high spin complexes of
(a) d⁷
(b) d⁸
(c) d⁴
(d) d⁹

Answer : B

Question. A compound has an empirical formula CoCl₃.5NH₃. When an aqueous solution of this compound is mixed with excess of silver nitrate, 2 moles of AgCl precipitates per mole of the compound. Hence the compound is
(a) [Co(NH₃)₅Cl₂]Cl
(b) [Co(NH₃)₅Cl]Cl₂
(c) [Co(NH₃)₅Cl₃]
(d) [Co(NH₃)₄Cl₂]Cl.NH₃

Answer : B

Question.Which ion would you expect to have the largest splitting of d-orbitals?
(a) [Fe(CN)₆]^4-
(b) [Fe(CN)₆]^3-
(c) [Fe(H₂O)₆]²⁺
(d) [Fe(H₂O)₆]³⁺

Answer : A

Question.Statement-1: [Co(NH₃)₃Cl₃] does not give white precipitate with AgNO₃ solution.
Statement-2: Chlorine is not present in the ionisable part of the given complex.
(a) If both the statements are true and statement-2 is the correct explanation of statement
(b) If both the statements are true but statement-2 is not the correct explanation of statement-1.
(c) If statement-1 is True and statement-2 is False.
(d) If statement-1 is False and statement-2 is True.

Answer : A

Question.The magnetic moment of a complex ion is 2.83 BM. The complex ion is
(a) [Cr(H₂O)₆]³⁺
(b) [Cu(CN)₄]^2-
(c) [V(H₂O)₆]³⁺
(d) [MnCl₄]^2-

Answer : C

Question. Which of the following complex has five unpaired electrons
(a) [Mn(H₂O)₆]²⁺
(b) [Mn(CN)₆]^3-
(c) [CrCl₃(H₂O)₃]
(d) [Ag(NH₃)₂]⁺

Answer : A

Question. Among the following ions, which one has the highest paramagnetism ?
(a) [Cr(H₂O)₆]³⁺
(b) [Fe(H₂O)₆]²⁺
(c) [Cu(H₂O)₆]²⁺
(d) [Zn(H₂O)₆]²⁺

Answer : B