CUET Chemistry MCQs Unit IX Coordination Compounds

Question : Ligand in a complex salt are
(a) anions linked by coordinate bonds to a central metal atom or ion
(b) cations linked by coordinate bonds to a central metal or ion
(c) molecules linked by coordinate bonds to a central metal or ion
(d) ions or molecules linked by coordinate bonds to a central atom or ion

Answer : C

Question : As per IUPAC nomenclature, the name of the complex [Co(H₂O)₄(NH₃)₂]Cl₃ is :
(a) Tetraaquadiaminecobalt (III) chloride
(b) Tetraaquadiamminecobalt (III) chloride
(c) Diaminetetraaquacoblat (II) chloride
(d) Diamminetetraaquacobalt (III) chloride

Answer : D

Question : The number of unpaired electrons in Ni(CO)₄ is 

(a) 0
(b) 1
(c) 3
(d) 5

Answer : A

Question : Which of the following does not have optical isomer? 

Answer : C

Question : According to the postulates of Werner for coordination compounds
(a) primary valency is ionizable
(b) secondary valency is ionizable
(c) primary and secondary valencies are non-ionizable
(d) only primary valency is non-ionizable.

Answer : A

Question : Which one is the most likely structure of CrCl₃. 6H₂O if 1/3 of total chlorine of the compound is precipitated by adding AgNO₃
(a) CrCl₃. 6H₂O
(b) [ Cr (H₂O)₃ Cl₃]. (H₂O)₃
(c) [ CrCl₂ (H₂O)₄ ] Cl . 2H₂O
(d) [ CrCl (H₂O)₅ ] Cl₂ . H₂O

Answer : C

Question : The coordination number of a central metal atom in a complex is determined by
(a) the number of ligands around a metal ion bonded by sigma and pi-bonds both
(b) the number of ligands around a metal ion bonded by pi-bonds
(c) the number of ligands around a metal ion bonded by sigma bonds
(d) the number of only anionic ligands bonded to the metal ion.

Answer : C

Question : The compound having the lowest oxidation state of iron is:
(a) K₄Fe(CN)₆ 
(b) K₂FeO₄
(c) Fe₂O₃ 
(d) Fe(CO)₅

Answer : D

Question : According to Lewis, the ligands are
(a) acidic in nature
(b) basic in nature
(c) some are acidic and others are basic
(d) neither acidic nor basic

Answer : B

Question : Which of the following does not form a chelate ?
(a) EDTA
(b) Oxalate
(c) Pyridine 
(d) Ethylenediamine

Answer : C

Question :  The IUPAC name of K₃[Ir(C₂O₄)₃] is
(a) potassium trioxalatoiridium (III)
(b) potassium trioxalatoiridate (III)
(c) potassium tris (oxalato) iridium (III)
(d) potassium tris (oxalato) iridate (III)

Answer : B

Question : O₂ is a
(a) Monodentate ligand 
(b) Bidenate ligand
(c) Tridentate ligand
(d) Hexadenate ligand

Answer : B

Question : Which of the following complexes are homoleptic ?
(i) 3[Co(NH₃ )₆ ]³⁺ (ii) [Co(NH₃ )4Cl]⁺
(iii) 2[Ni(CN)4 ]^2- (iv) [Ni(NH₃ )4Cl₂ ]
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iii)

Answer : C

Question : K₃[Al(C₂O₄ )₃] is called
(a) Potassium aluminooxalate
(b) Potassium trioxalatoaluminate (III)
(c) Potassium aluminium (III) oxalate
(d) Potassium trioxalatoaluminate (VI)

Answer : C

Question : The IUPAC name of [Ni(NH₃)₄] [NiCl₄] is
(a) Tetrachloronickel (II) - tetraamminenickel (II)
(b) Tetraamminenickel (II) - tetrachloronickel (II)
(c) Tetraamminenickel (II) - tetrachloronickelate (II)
(d) Tetrachloronickel (II) - tetrachloronickelate (0)

Answer : C

Question : As per IUPAC nomenclature, the name of the complex [Co(H₂O)₄(NH₃)₂]Cl₃ is :
(a) Tetraaquadiaminecobalt (III) chloride
(b) Tetraaquadiamminecobalt (III) chloride
(c) Diaminetetraaquacobalt (II) chloride
(d) Diamminetetraaquacobalt (III) chloride

Answer : D

Question : During estimation of nickel, we prepare nickel dimethylglyoxime, a scarlet red solid. This compound is ______.
(a) ionic   
(b) covalent
(c) metallic
(d) non-ionic complex.

Answer : D

Question :  Which of the following complex has zero magnetic moment (spin only)?

Answer : C

Question :  In the isoelectronic series of metal carbonyl, the CO bond strength is expected to increase in the order:

Answer : B

Question : Mercuric chloride is soluble in KI solution due to :

(a) the formation of complex ion
(b) common iodide ion
(c) none of the above
(d) both (a) and (b)

Answer : A

Question : An aqueous solution of CoCl₂ on addition of excess of concentrated HCl turns blue due to formation of : 

Answer : C

Question : One mole of the complex compound Co(NH₃)₅Cl₃, gives 3 moles of ions on dissolution in water. One mole of the same complex reacts with two moles of AgNO₃ solution to yield two moles of AgCl (s). The structure of the complex is
(a) [Co(NH₃)₃Cl₃]. 2 NH₃
(b) [Co(NH₃)₄Cl₂] Cl . NH₃
(c) [Co(NH₃)₄Cl] Cl₂. NH₃
(d) [Co(NH₃)₅Cl] Cl₂

Answer : D

Question : The solution of K₄[Fe(CN)₆] in water will
(a) give a test K⁺ 
(b) give a test Fe²⁺
(c) give a test of CN–
(d) give a test of [Fe(CN)₆]^4–

Answer : A

Question : The coordination number and the oxidation state of the element ‘E’ in the complex [E (en)2 (C2O4)]NO2 (where (en) is ethylene diamine) are, respectively,
(a) 6 and 2
(b) 4 and 2
(c) 4 and 3
(d) 6 and 3

Answer : D

Question : An example of ambidentate ligand is
(a) Ammine
(b) Aquo
(c) Chloro
(d) Thiocyanato

Answer : D

Question : Which one of the following is NOT a ligand ?
(a) PH₃ 
(b) NO+
(c) Na+
(d) F–

Answer : C

Question :  Choose the correct statement.
(a) Coordination number has nothing to do with the number of groups or molecules attached to the central atom
(b) Coordination number is the number of coordinating sites of all the ligands connected to the central atom or the number of coordinate bonds formed by the metal atom with ligands
(c) Werner’s coordination theory postulates only one type of valency
(d) All the above are correct

Answer : B

Question : Which of the following complexes are heteroleptic ?
(i) 3[Cr(NH₃ )₆ ]³⁺ (ii) [Fe(NH₃)₄Cl₂ ]⁺
(iii) 4[Mn(CN)₆ ]^2- (iv) [Co(NH₃)4Cl₂ ]
(a) (i), (iv)
(b) (ii) and (iv)
(c) (i) and (ii)
(d) (i) and (iv)

Answer : B

Question : The IUPAC name of the coordination compound K₃[Fe(CN)₆ ] is
(a) Tripotassium hexacyanoiron (II)
(b) Potassium hexacyanoiron (II)
(c) Potassium hexacyanoferrate (III)
(d) Potassium hexacyanoferrate (II)

Answer : C

Question : The IUPAC name of the complex [Co(NH₃)₄(H₂O)Cl]Cl₂ is
(a) aquatetramminechloridocobalt (III) chloride
(b) chloridoaquatetramminechloridocobalt (III) chloride
(c) chloridoaquatetramminechloridocobalt (III) chloride
(d) tetrammineaquachloridocobalt (III) chloride

Answer : D

Question : Which of the following metal ions will form complexes with the same magnetic moment and geometry irrespective of the nature of ligands? 
(a) Ni²⁺ 
 (b) Fe²⁺
(c) Cu²⁺ 
(d) Co²⁺

Answer : C

Question :  The IUPAC name of the complex Hg [Co(CNS )₄] is

(a) mercury tetrathiocyanatocobaltate (II)
(b) mercury cobalttetrasulphocyano (II)
(c) mercury tetrasulphocyanidecobalt (II)
(d) tetrasulphocyantocobalt mercurate (II)

Answer : A

Question :

(a) 16
(b) 26
(c) 36
(d) 46

Answer : C

Question : The correct order for the wavelength of absorption in the visible region is : 

Answer : A

Question : K₄[Fe(CN)₆ ] is a :
(a) double salt
(b) complex compound
(c) acid
(d) base

Answer : B

Question : In Ni(CO)4 – , oxidation number of Ni is :
(a) 4
(b) – 4
(c) 0
(d) + 2

Answer : C

Question : The ligand N(CH₂CH₂NH₂)₃ is
(a) tridentate
(b) pentadentate
(c) tetradentate
(d) bidentate

Answer : C

Question : Which one does not belong to ligand?
(a) PH₃ 
(b) NO+
(c) BF₃ 
(d) Cl–

Answer : C

Question : The stabilisation of cooordination compounds due to chelation is called the chelate effect. Which of the following is the most stable complex species ?
(a) [Fe(CO)₅ ]     
(b) 3[Fe(CN)₆ ] -
(c) 3[Fe(C₂O₄ )₃ ] -    
(d) 3[Fe(H₂O)₆ ] -

Answer : C

Question : Central atoms/ions in coordination compounds are.
(a) Lewis acid
(b) Lewis bases
(c) Neutral molecules
(d) All of these

Answer : A

Question : The IUPAC name of K₂[PtCl₆] is
(a) hexachloroplatinate potassium
(b) potassium hexachloroplatinate (IV)
(c) potassium hexachloroplatinate
(d) potassium hexachloroplatinum (IV)

Answer : B

Question : Which statement is true for ferrocene?
(a) All Fe-C are of equal length
(b) It has sandwich type structure
(c) It was the first discovered organometallic compound
(d) All of these.

Answer : D

Question :  Silver chloride dissolves in
(a) Water   
(b) Conc. HCl
(c) NH₄OH 
(d) CCl₄

Answer : C

Question : The reagent commonly used to determine hardness of water titrimetrically is

(a) oxalic acid
(b) disodium salt of EDTA
(c) sodium citrate
(d) sodium thiosulphate

Answer : B

Question : When AgNO₃ is added to a solution of Co(NH₃)₅Cl₃, the precipitate of AgCl shows two ionisable chloride ions. This means :
(a) Two chlorine atoms satisfy primary valency and one secondary valency
(b) One chlorine atom satisfies primary as well as secondary valency
(c) Three chlorine atoms satisfy primary valency
(d) Three chlorine atoms satisfy secondary valency

Answer : A

Question : [EDTA]^4- is a :
(a) monodentate ligand
(b) bidentate ligand
(c) quadridentate ligand
(d) hexadentate ligand

Answer : D

Question : A bidenate ligand always
(a) has bonds formed to two metals ions
(b) has a charge of +2 or – 2
(c) forms complex ions with a charge of +2 or –2
(d) has two donor atoms forming simultaneously two sigma (Σ) bonds.

Answer : B

Question : Which one of the following ligands forms a chelate
(a) Acetate
(b) Oxalate
(c) Ammonia
(d) Cyanide

Answer : B

Question : The hypothetical complex chlorodiaquatriamminecobalt (III) chloride can be represented as
(a) [CoCl(NH₃)₃(H₂O)₂]Cl₂
(b) [Co(NH₃)₃(H₂O)Cl₃]
(c) [Co(NH₂)₃(H2O)2 Cl]
(d) [Co(NH₃)₃(H₂O)₃]Cl₃

Answer : A

Question : 

(a) linkage isomerism
(b) geometrical isomerism
(c) optical isomerism
(d) none of the above

Answer : B

Question : What is the denticity of the ligand ethylenediaminetetra actetate ion?
(a) 4
(b) 2
(c) 6
(d) 1

Answer : C

Question : The ligands in anti-cancer drug cis-platin are 
(a) NH₃, CI
(b) NH₃, H₂O
(c) Cl, H₂O 
(d) NO, Cl

Answer : A

Question : Which of the following is not considered as an organometallic compound? 

(a) cis-platin   
(b) Ferrocene
(c) Zeise's salt
(d) Grignard reagent

Answer : A

Question : The number of ions formed on dissolving one molecule of FeSO₄(NH₄)2SO₄.6H₂O in water is:
(a) 4
(b) 5
(c) 3
(d) 6

Answer : B

Question : Coordination number of Ni in [Ni(C₂O₄)₃]^4– is
(a) 3
(b) 6
(c) 4
(d) 5

Answer : B

Question : NH₂-NH₂ serves as
(a) Monodentate ligand
(b) Chelating ligand
(c) Bridging ligand
(d) Both (a) and (c)

Answer : C

Question : Which of the following species is not expected to be a ligand?
(a) NO
(b) NH₄
(c) NH₂CH₂CH₂NH₂ 
(d) Both (a) and (b)

Answer : B

Question :  Among the following the compound that is both paramagnetic and coloured is

Answer : A

Question : Which of the following postulates of Werner’s theory is incorrect?
(a) Primary valencies are satisfied by negative ions.
(b) Secondary valencies are satisfied by neutral molecules or negative ions.
(c) Secondary valence is equal to the coordination number and it depends upon the nature of ligand attached to metal.
(d) The ions/ groups bound by the secondary linkages to the metal have charecteristic spatial arrangements.

Answer : C

Question : Some salts although containing two different metallic elements give test for only one of them in solution. Such salts are
(a) complex
(b) double salts
(c) normal salts
(d) None of these

Answer : A

Question : Which ligand is expected to be bidentate?
(a) 2 C₂O²_4- 
(b) CH₃C = N
(c) Br –
(d) CH₃NH₂

Answer : A

Question : Chemical formula for iron (III) hexacyanoferrate (II) is
(a) Fe[Fe(CN)₆]
(b) Fe₃[Fe(CN)₆]
(c) Fe₃[Fe(CN)₆]₄ 
(d) Fe₄[Fe(CN)₆]₃ 

Answer : A

Question : The organometallic compound is :

(a) Ti(OCOCH₃ )₄ 
(b) Ti(C₂H₅ )₄
(c) Ti(OC₆H₅ )₄    
(d) Ti(OC₂H₅)₄

Answer : B

Question : The oxidation state of Cr in [Cr(NH₃ )4Cl₂ ]⁺ is
(a) 0
(b) + 1
(c) + 2
(d) + 3

Answer : D

Question : The IUPAC name for the complex [Co(ONO)(NH₃)₅]Cl₂ is
(a) pentaamminenitrito-N-cobalt(II) chloride
(b) pentaamminenitrito-N-cobalt(III) chloride
(c) nitrito-N-pentaamminecobalt(III) chloride
(d) nitrito-N-pentaamminecobalt(II) chloride

Answer : B

Question : CrCl₃ has primary valence of
(a) 3
(b) 4
(c) 2
(d) 1

Answer : A

Question : An ambident ligand is one which
(a) is linked to the metal atom through two donor atoms
(b) has two donor atoms, but only one of them has the capacity to form a coordinate bond [or a sigma (Σ) bond]
(c) has two donor atoms, but either of two can form a coordinate bond
(d) forms chelate rings.

Answer : C

Question : The diamagnetic species is 

Answer : A

Question : A chelating agent has two or more than two donor atoms to bind to a single metal ion. Which of the following is not a chelating agent ?
(a) thiosulphato
(b) oxalato
(c) glycinato
(d) ethane - 1, 2-diamine

Answer : A

Question : In the coordination compound, K₄[Ni(CN)₄], the oxidation state of nickel is
(a) 0
(b) +1
(c) +2
(d) –1

Answer : A