📘 Chapter 5 – Coordination Compounds

MCQ Type | 0.5 Mark Each | Application-Based

Q1.

A coordination compound shows optical isomerism when:
एक समन्वय यौगिक प्रकाशीय समावयवता दर्शाता है जब:

A. It has square planar geometry / इसका ज्यामिति square planar हो
B. It contains chelating ligands / इसमें chelating ligands हों
C. It has tetrahedral geometry / इसका ज्यामिति tetrahedral हो
D. It contains only monodentate ligands / इसमें केवल monodentate ligand हों

✅ Answer:
B. Chelating ligands / Chelating ligand

Explanation (English):
Optical isomerism arises due to asymmetric arrangement, commonly seen in complexes containing chelating ligands like en.

Q2.

Which complex will NOT show cis–trans isomerism?
कौन-सा complex cis–trans समावयवता नहीं दर्शाएगा?

A. [Pt(NH₃)₂Cl₂]
B. [Co(NH₃)₄Cl₂]⁺
C. [Ni(CO)₄]
D. [Cr(en)₂Cl₂]⁺

✅ Answer:
C. [Ni(CO)₄]

Explanation (English):
[Ni(CO)₄] is tetrahedral, and tetrahedral complexes do not show geometrical isomerism.

Q3.

The coordination number of Fe in [Fe(C₂O₄)₃]³⁻ is:
[Fe(C₂O₄)₃]³⁻ में Fe की coordination number है:

A. 3 / तीन
B. 4 / चार
C. 6 / छह
D. 2 / दो

✅ Answer:
C. 6 / छह

Explanation (English):
Oxalate (C₂O₄²⁻) is bidentate; 3 ligands × 2 donor atoms = 6.

Q4.

Which ligand causes maximum crystal field splitting?
कौन-सा ligand अधिकतम crystal field splitting उत्पन्न करता है?

A. F⁻ / फ्लोराइड
B. H₂O / जल
C. NH₃ / अमोनिया
D. CN⁻ / सायनाइड

✅ Answer:
D. CN⁻ / सायनाइड

Explanation (English):
CN⁻ is a strong field ligand as per spectrochemical series, causing maximum Δ₀.

Q5.

Which complex is diamagnetic?
कौन-सा complex diamagnetic है?

A. [Fe(H₂O)₆]²⁺
B. [CoF₆]³⁻
C. [Ni(CN)₄]²⁻
D. [Mn(H₂O)₆]²⁺

✅ Answer:
C. [Ni(CN)₄]²⁻

Explanation (English):
Strong field ligand CN⁻ pairs electrons in Ni²⁺ (d⁸), making it diamagnetic.

Q6.

Which property helps in separation of optical isomers?
कौन-सा गुण प्रकाशीय समावयवों को अलग करने में सहायक है?

A. Solubility / विलेयता
B. Melting point / गलनांक
C. Rotation of plane-polarised light / ध्रुवीकृत प्रकाश का घूर्णन
D. Density / घनत्व

✅ Answer:
C. Rotation of plane-polarised light / ध्रुवीकृत प्रकाश का घूर्णन

Explanation (English):
Optical isomers rotate plane-polarised light in opposite directions.

Q7.

Which complex has square planar geometry?
कौन-सा complex square planar ज्यामिति दर्शाता है?

A. [Ni(CO)₄]
B. [Pt(NH₃)₂Cl₂]
C. [Zn(NH₃)₄]²⁺
D. [Fe(H₂O)₆]²⁺

✅ Answer:
B. [Pt(NH₃)₂Cl₂]

Explanation (English):
d⁸ metal ions like Pt(II) commonly form square planar complexes.

Q8.

The oxidation state of Co in [Co(NH₃)₅Cl]Cl₂ is:
[Co(NH₃)₅Cl]Cl₂ में Co की oxidation state है:

A. +1 / +1
B. +2 / +2
C. +3 / +3
D. 0 / शून्य

✅ Answer:
C. +3 / +3

Explanation (English):
Overall charge balance gives oxidation state of Co as +3.

Q9.

Which ligand can link through two different donor atoms?
कौन-सा ligand दो विभिन्न donor atoms से जुड़ सकता है?

A. NH₃
B. NO₂⁻
C. OH⁻
D. H₂O

✅ Answer:
B. NO₂⁻

Explanation (English):
NO₂⁻ is an ambidentate ligand; it can coordinate via N or O.

Q10.

Linkage isomerism is possible due to presence of:
Linkage isomerism किसके कारण होती है?

A. Chelating ligands
B. Ambidentate ligands
C. Polydentate ligands
D. Neutral ligands

✅ Answer:
B. Ambidentate ligands / Ambidentate ligand

Explanation (English):
Ambidentate ligands can attach through different atoms, causing linkage isomerism.

Q11.

Which complex will show ionisation isomerism?
कौन-सा complex ionisation isomerism दर्शाएगा?

A. [Co(NH₃)₆]Cl₃
B. [Co(NH₃)₅SO₄]Br
C. [Ni(CO)₄]
D. [Zn(NH₃)₄]²⁺

✅ Answer:
B. [Co(NH₃)₅SO₄]Br

Explanation (English):
Exchange between counter ion and ligand causes ionisation isomerism.

Q12.

Which coordination compound obeys Werner’s theory completely?
कौन-सा यौगिक Werner सिद्धांत का पूर्ण पालन करता है?

A. [Co(NH₃)₆]Cl₃
B. K₄[Fe(CN)₆]
C. [Ni(CO)₄]
D. All of these

✅ Answer:
D. All of these / सभी

Explanation (English):
All listed compounds fit Werner’s primary and secondary valency concept.

Q13.

Chelate effect increases the:
Chelate effect किसे बढ़ाता है?

A. Colour / रंग
B. Stability / स्थिरता
C. Conductivity / चालकता
D. Solubility / विलेयता

✅ Answer:
B. Stability / स्थिरता

Explanation (English):
Chelating ligands form ring structures, increasing complex stability.

Q14.

Which metal ion forms coloured compounds due to d–d transition?
कौन-सा धातु आयन d–d संक्रमण के कारण रंगीन यौगिक बनाता है?

A. Zn²⁺
B. Cu²⁺
C. Sc³⁺
D. Cd²⁺

✅ Answer:
B. Cu²⁺

Explanation (English):
Cu²⁺ has partially filled d-orbitals enabling d–d transitions.

Q15.

Which complex will show fac–mer isomerism?
कौन-सा complex fac–mer समावयवता दर्शाएगा?

A. [MA₆]
B. [MA₄B₂]
C. [MA₃B₃]
D. [MAB₅]

✅ Answer:
C. [MA₃B₃]

Explanation (English):
fac–mer isomerism is shown by octahedral complexes of type MA₃B₃.

Q16.

Which ligand forms most stable complex with metal ion?
कौन-सा ligand धातु आयन के साथ सबसे स्थिर complex बनाता है?

A. NH₃
B. H₂O
C. en
D. Cl⁻

✅ Answer:
C. en (ethylenediamine)

Explanation (English):
en is a bidentate chelating ligand, increasing stability.

Q17.

Which compound is used in cancer chemotherapy?
कौन-सा यौगिक कैंसर उपचार में उपयोग होता है?

A. Cis-platin
B. Zeise’s salt
C. Tollen’s reagent
D. Fehling solution

✅ Answer:
A. Cis-platin

Explanation (English):
Cis-platin is an important coordination compound used in cancer treatment.

Q18.

Which complex shows coordination isomerism?
कौन-सा complex coordination isomerism दर्शाता है?

A. [Co(NH₃)₆]Cl₃
B. [Cr(NH₃)₆][Co(CN)₆]
C. [Ni(CO)₄]
D. K₃[Fe(CN)₆]

✅ Answer:
B. [Cr(NH₃)₆][Co(CN)₆]

Explanation (English):
Interchange of ligands between cationic and anionic complexes causes coordination isomerism.

Q19.

Which ligand is neutral?
कौन-सा ligand उदासीन (neutral) है?

A. CN⁻
B. OH⁻
C. NH₃
D. Cl⁻

✅ Answer:
C. NH₃

Explanation (English):
NH₃ donates lone pair without charge.

Q20.

In octahedral complexes, crystal field splitting produces:
Octahedral complexes में crystal field splitting से बनते हैं:

A. t₂g and e_g
B. s and p
C. d_xy and d_z²
D. σ and π

✅ Answer:
A. t₂g and e_g

Explanation (English):
In octahedral field, d-orbitals split into lower t₂g and higher e_g levels.

Q21.

Which complex is used in photography?
कौन-सा complex फोटोग्राफी में प्रयुक्त होता है?

A. [Ag(CN)₂]⁻
B. [Fe(CN)₆]³⁻
C. [Cu(NH₃)₄]²⁺
D. [Zn(OH)₄]²⁻

✅ Answer:
A. [Ag(CN)₂]⁻

Explanation (English):
Silver cyanide complex is used in photographic fixing process.

Q22.

Which complex ion has coordination number 2?
किस complex ion की coordination number 2 है?

A. [Ag(NH₃)₂]⁺
B. [Ni(CO)₄]
C. [Fe(CN)₆]³⁻
D. [Cu(NH₃)₄]²⁺

✅ Answer:
A. [Ag(NH₃)₂]⁺

Explanation (English):
Ag⁺ commonly forms linear complexes with coordination number 2.

Q23.

Which ligand causes chelation?
कौन-सा ligand chelation करता है?

A. NH₃
B. EDTA⁴⁻
C. Cl⁻
D. CO

✅ Answer:
B. EDTA⁴⁻

Explanation (English):
EDTA is hexadentate and forms chelate rings.

Q24.

Which metal ion does NOT show variable oxidation states?
कौन-सा धातु आयन परिवर्तनशील oxidation state नहीं दर्शाता?

A. Fe
B. Cu
C. Zn
D. Co

✅ Answer:
C. Zn

Explanation (English):
Zn has completely filled d¹⁰ configuration and shows fixed oxidation state.

Q25.

Which phenomenon explains colour in coordination compounds?
समन्वय यौगिकों में रंग किस घटना से उत्पन्न होता है?

A. Nuclear transition
B. Charge transfer
C. d–d transition
D. f–f transition

✅ Answer:
C. d–d transition

Explanation (English):
Absorption of visible light promotes d-electron transition, causing colour.

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Q26.

Which complex ion will show optical isomerism?
कौन-सा complex ion प्रकाशीय समावयवता दर्शाएगा?

A. [Co(NH₃)₆]³⁺
B. [Cr(en)₃]³⁺
C. [Ni(CO)₄]
D. [PtCl₄]²⁻

✅ Answer:
B. [Cr(en)₃]³⁺ / [Cr(en)₃]³⁺

Explanation (English):
Octahedral complexes with three bidentate ligands like en are chiral and show optical isomerism.

Q27.

The coordination number of central metal in [Cu(NH₃)₄]²⁺ is:
[Cu(NH₃)₄]²⁺ में केंद्रीय धातु की coordination number है:

A. 2 / दो
B. 3 / तीन
C. 4 / चार
D. 6 / छह

✅ Answer:
C. 4 / चार

Explanation (English):
Four NH₃ ligands coordinate to Cu²⁺ giving coordination number 4.

Q28.

Which complex will show geometrical isomerism?
कौन-सा complex ज्यामितीय समावयवता दर्शाएगा?

A. [Ni(CO)₄]
B. [Pt(NH₃)₂Cl₂]
C. [Co(NH₃)₆]³⁺
D. [Zn(NH₃)₄]²⁺

✅ Answer:
B. [Pt(NH₃)₂Cl₂]

Explanation (English):
Square planar complexes of type MA₂B₂ show cis–trans isomerism.

Q29.

Which ligand is monodentate?
कौन-सा ligand एकदन्त (monodentate) है?

A. en
B. EDTA⁴⁻
C. NH₃
D. C₂O₄²⁻

✅ Answer:
C. NH₃ / NH₃

Explanation (English):
NH₃ donates only one lone pair, hence monodentate.

Q30.

Which metal ion commonly forms square planar complexes?
कौन-सा धातु आयन सामान्यतः square planar complex बनाता है?

A. Zn²⁺
B. Fe²⁺
C. Ni²⁺
D. Mn²⁺

✅ Answer:
C. Ni²⁺

Explanation (English):
d⁸ metal ions like Ni²⁺ often form square planar complexes.

Q31.

Which complex is used as an anti-cancer drug?
कौन-सा complex कैंसर-रोधी औषधि के रूप में प्रयुक्त होता है?

A. Trans-platin
B. Cis-platin
C. Zeise’s salt
D. [Fe(CN)₆]³⁻

✅ Answer:
B. Cis-platin / Cis-platin

Explanation (English):
Cis-platin binds with DNA and is used in chemotherapy.

Q32.

Which ligand is strongest field ligand?
कौन-सा ligand सबसे strong field ligand है?

A. F⁻
B. H₂O
C. NH₃
D. CN⁻

✅ Answer:
D. CN⁻ / CN⁻

Explanation (English):
CN⁻ is at the strong field end of spectrochemical series.

Q33.

Which complex will be paramagnetic?
कौन-सा complex paramagnetic होगा?

A. [Ni(CO)₄]
B. [Zn(NH₃)₄]²⁺
C. [Fe(H₂O)₆]³⁺
D. [Pt(NH₃)₂Cl₂]

✅ Answer:
C. [Fe(H₂O)₆]³⁺

Explanation (English):
Fe³⁺ (d⁵) with weak ligand H₂O has unpaired electrons.

Q34.

Which type of isomerism is shown by [Co(NH₃)₅Cl]SO₄?
[Co(NH₃)₅Cl]SO₄ किस प्रकार की समावयवता दर्शाता है?

A. Linkage
B. Ionisation
C. Optical
D. Coordination

✅ Answer:
B. Ionisation / आयनीकरण

Explanation (English):
Exchange of Cl⁻ and SO₄²⁻ between coordination sphere and ionisable sphere causes ionisation isomerism.

Q35.

Which ligand can donate more than one pair of electrons?
कौन-सा ligand एक से अधिक electron pair दान कर सकता है?

A. NH₃
B. Cl⁻
C. en
D. CO

✅ Answer:
C. en / en

Explanation (English):
en is bidentate and donates two lone pairs.

Q36.

The shape of [Ag(NH₃)₂]⁺ is:
[Ag(NH₃)₂]⁺ का आकार है:

A. Tetrahedral / चतुष्फलकीय
B. Square planar / वर्ग समतलीय
C. Linear / रेखीय
D. Octahedral / अष्टफलक

✅ Answer:
C. Linear / रेखीय

Explanation (English):
Coordination number 2 complexes are linear.

Q37.

Which complex will NOT show any isomerism?
कौन-सा complex कोई समावयवता नहीं दर्शाएगा?

A. [Co(NH₃)₆]³⁺
B. [Pt(NH₃)₂Cl₂]
C. [Cr(en)₂Cl₂]⁺
D. [Co(NH₃)₄Cl₂]⁺

✅ Answer:
A. [Co(NH₃)₆]³⁺

Explanation (English):
All ligands are same, hence no isomerism possible.

Q38.

Which factor increases stability of coordination compounds?
समन्वय यौगिकों की स्थिरता किससे बढ़ती है?

A. Monodentate ligands
B. High oxidation state only
C. Chelation
D. Weak ligands

✅ Answer:
C. Chelation / Chelation

Explanation (English):
Chelation forms ring structures, increasing stability (chelate effect).

Q39.

Which complex shows fac–mer isomerism?
कौन-सा complex fac–mer समावयवता दर्शाता है?

A. [MA₂B₄]
B. [MA₃B₃]
C. [MA₆]
D. [MAB₅]

✅ Answer:
B. [MA₃B₃]

Explanation (English):
Octahedral complexes of type MA₃B₃ show fac–mer isomerism.

Q40.

Which metal ion has d⁰ configuration?
किस धातु आयन की d⁰ संरचना होती है?

A. Ti⁴⁺
B. Fe²⁺
C. Cu²⁺
D. Zn²⁺

✅ Answer:
A. Ti⁴⁺

Explanation (English):
Ti⁴⁺ loses all d-electrons giving d⁰ configuration.

Q41.

Which ligand forms maximum number of chelate rings?
कौन-सा ligand अधिकतम chelate rings बनाता है?

A. NH₃
B. en
C. EDTA⁴⁻
D. C₂O₄²⁻

✅ Answer:
C. EDTA⁴⁻

Explanation (English):
EDTA is hexadentate and forms multiple chelate rings.

Q42.

The colour of coordination compounds is mainly due to:
समन्वय यौगिकों का रंग मुख्यतः किस कारण होता है?

A. Nuclear transition
B. f–f transition
C. d–d transition
D. Ionisation

✅ Answer:
C. d–d transition / d–d संक्रमण

Explanation (English):
Absorption of visible light promotes d-electron transitions.

Q43.

Which complex is tetrahedral?
कौन-सा complex tetrahedral है?

A. [PtCl₄]²⁻
B. [Ni(CN)₄]²⁻
C. [Ni(CO)₄]
D. [Cu(NH₃)₄]²⁺

✅ Answer:
C. [Ni(CO)₄]

Explanation (English):
[Ni(CO)₄] is a classic tetrahedral complex.

Q44.

Which is a neutral ligand?
कौन-सा neutral ligand है?

A. CN⁻
B. OH⁻
C. NH₃
D. Cl⁻

✅ Answer:
C. NH₃ / NH₃

Explanation (English):
NH₃ has no charge and donates lone pair.

Q45.

Which complex will show linkage isomerism?
कौन-सा complex linkage isomerism दर्शाएगा?

A. [Co(NH₃)₆]³⁺
B. [Co(NH₃)₅(NO₂)]²⁺
C. [Ni(CO)₄]
D. [Zn(NH₃)₄]²⁺

✅ Answer:
B. [Co(NH₃)₅(NO₂)]²⁺

Explanation (English):
NO₂⁻ can coordinate through N or O causing linkage isomerism.

Q46.

Which metal ion does NOT show variable oxidation states?
कौन-सा धातु आयन परिवर्तनशील oxidation state नहीं दिखाता?

A. Fe
B. Mn
C. Zn
D. Co

✅ Answer:
C. Zn / Zn

Explanation (English):
Zn has stable d¹⁰ configuration.

Q47.

Which complex has coordination number 6?
कौन-सा complex की coordination number 6 है?

A. [Ag(NH₃)₂]⁺
B. [Fe(CN)₆]³⁻
C. [Ni(CO)₄]
D. [Cu(NH₃)₄]²⁺

✅ Answer:
B. [Fe(CN)₆]³⁻

Explanation (English):
Six CN⁻ ligands coordinate to Fe³⁺.

Q48.

Which theory explains bonding in coordination compounds?
समन्वय यौगिकों में बंधन किस सिद्धांत से समझाया जाता है?

A. VBT
B. CFT
C. MOT
D. All of these

✅ Answer:
D. All of these / सभी

Explanation (English):
VBT, CFT and MOT all explain different aspects of bonding.

Q49.

Which complex is used in photography fixing?
फोटोग्राफी fixing में कौन-सा complex प्रयुक्त होता है?

A. [Ag(CN)₂]⁻
B. [Cu(NH₃)₄]²⁺
C. [Fe(CN)₆]³⁻
D. [Zn(OH)₄]²⁻

✅ Answer:
A. [Ag(CN)₂]⁻

Explanation (English):
Silver cyanide complex dissolves AgBr during fixing.

Q50.

Which ligand is ambidentate?
कौन-सा ligand ambidentate है?

A. NH₃
B. CO
C. NO₂⁻
D. en

✅ Answer:
C. NO₂⁻ / NO₂⁻

Explanation (English):
NO₂⁻ can bind through N or O atoms.

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🔹 Question Format: MCQ

Marks per question: 0.5
Total questions: 50
Question type: Knowledge based

Q1. According to Werner’s theory, primary valency is satisfied by:

वर्नर सिद्धान्त के अनुसार, प्राथमिक संयोजकता की पूर्ति होती है —

A. Ligands / लिगैंड
B. Anions / ऋणायन
C. Neutral molecules / उदासीन अणु
D. Coordination number / समन्वय संख्या

✅ Answer:
English: B. Anions
Hindi: B. ऋणायन

Explanation (English):
Primary valency corresponds to oxidation state and is satisfied by anions.

Q2. The coordination number of cobalt in is:

में कोबाल्ट की समन्वय संख्या है —

A. 3 / तीन
B. 4 / चार
C. 5 / पाँच
D. 6 / छह

✅ Answer:
English: D. 6
Hindi: D. छह

Explanation (English):
Six NH₃ ligands are directly attached to cobalt.

Q3. Which of the following is a monodentate ligand?

निम्न में से कौन-सा एकदन्त (monodentate) लिगैंड है?

A. EDTA⁴⁻
B. C₂O₄²⁻
C. NH₃
D. en

✅ Answer:
English: C. NH₃
Hindi: C. NH₃

Explanation (English):
NH₃ donates only one pair of electrons.

Q4. Oxidation state of Fe in is:

में Fe की ऑक्सीकरण अवस्था है —

A. +1
B. +2
C. +3
D. +4

✅ Answer:
English: B. +2
Hindi: B. +2

Explanation (English):
Each CN⁻ = −1 → Total −6
Overall charge −4 → Fe = +2

Q5. Which ligand can attach through two different donor atoms?

कौन-सा लिगैंड दो भिन्न donor परमाणुओं से जुड़ सकता है?

A. NH₃
B. NO₂⁻
C. OH⁻
D. H₂O

✅ Answer:
English: B. NO₂⁻
Hindi: B. NO₂⁻

Explanation (English):
NO₂⁻ can bind through nitrogen or oxygen → ambidentate ligand.

Q6. Which complex shows ionisation isomerism?

कौन-सा संकुल आयनीकरण समावयवता दर्शाता है?

A. [Co(NH₃)₅SO₄]Br
B. [Ni(CO)₄]
C. [Pt(NH₃)₂Cl₂]
D. [Fe(CN)₆]³⁻

✅ Answer:
English: A
Hindi: A

Explanation (English):
Exchange of SO₄²⁻ and Br⁻ causes ionisation isomerism.

Q7. The shape of is:

की आकृति है —

A. Square planar / वर्ग समतलीय
B. Tetrahedral / चतुष्फलकीय
C. Octahedral / अष्टफलकीय
D. Linear / रेखीय

✅ Answer:
English: B. Tetrahedral
Hindi: B. चतुष्फलकीय

Explanation (English):
Nickel forms sp³ hybridisation in this complex.

Q8. Which of the following is a chelating ligand?

निम्न में से कौन-सा chelating लिगैंड है?

A. NH₃
B. H₂O
C. EDTA⁴⁻
D. Cl⁻

✅ Answer:
English: C. EDTA⁴⁻
Hindi: C. EDTA⁴⁻

Explanation (English):
EDTA forms multiple bonds with a metal ion.

Q9. Cis–trans isomerism is possible in:

Cis–trans समावयवता पाई जाती है —

A. Tetrahedral complexes
B. Linear complexes
C. Square planar complexes
D. All complexes

✅ Answer:
English: C. Square planar complexes
Hindi: C. वर्ग समतलीय संकुल

Explanation (English):
Different relative positions of ligands cause cis–trans isomerism.

Q10. The colour of coordination compounds is mainly due to:

समन्वय यौगिकों का रंग मुख्यतः किस कारण होता है?

A. Nuclear transition
B. d–d transition
C. f–f transition
D. Charge on ion

✅ Answer:
English: B. d–d transition
Hindi: B. d–d संक्रमण

Explanation (English):
Absorption of visible light promotes electrons between d-orbitals.

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📘 Chapter 5 – Coordination Compounds

Class 12 Chemistry | NCERT

🔹 Question Format: MCQ

Marks per question: 0.5
Total questions: 50
Question type: Knowledge based
Question language: English + Hindi
Options language: English + Hindi
Answer language: English + Hindi
Explanation language: English only
Source: NCERT Book PDF + Project Files ONLY

🔢 MCQs (1–10)

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Q1. According to Werner’s theory, primary valency is satisfied by:

वर्नर सिद्धान्त के अनुसार, प्राथमिक संयोजकता की पूर्ति होती है —

A. Ligands / लिगैंड
B. Anions / ऋणायन
C. Neutral molecules / उदासीन अणु
D. Coordination number / समन्वय संख्या

✅ Answer:
English: B. Anions
Hindi: B. ऋणायन

Explanation (English):
Primary valency corresponds to oxidation state and is satisfied by anions.

Q2. The coordination number of cobalt in is:

में कोबाल्ट की समन्वय संख्या है —

A. 3 / तीन
B. 4 / चार
C. 5 / पाँच
D. 6 / छह

✅ Answer:
English: D. 6
Hindi: D. छह

Explanation (English):
Six NH₃ ligands are directly attached to cobalt.

Q3. Which of the following is a monodentate ligand?

निम्न में से कौन-सा एकदन्त (monodentate) लिगैंड है?

A. EDTA⁴⁻
B. C₂O₄²⁻
C. NH₃
D. en

✅ Answer:
English: C. NH₃
Hindi: C. NH₃

Explanation (English):
NH₃ donates only one pair of electrons.

Q4. Oxidation state of Fe in is:

में Fe की ऑक्सीकरण अवस्था है —

A. +1
B. +2
C. +3
D. +4

✅ Answer:
English: B. +2
Hindi: B. +2

Explanation (English):
Each CN⁻ = −1 → Total −6
Overall charge −4 → Fe = +2

Q5. Which ligand can attach through two different donor atoms?

कौन-सा लिगैंड दो भिन्न donor परमाणुओं से जुड़ सकता है?

A. NH₃
B. NO₂⁻
C. OH⁻
D. H₂O

✅ Answer:
English: B. NO₂⁻
Hindi: B. NO₂⁻

Explanation (English):
NO₂⁻ can bind through nitrogen or oxygen → ambidentate ligand.

Q6. Which complex shows ionisation isomerism?

कौन-सा संकुल आयनीकरण समावयवता दर्शाता है?

A. [Co(NH₃)₅SO₄]Br
B. [Ni(CO)₄]
C. [Pt(NH₃)₂Cl₂]
D. [Fe(CN)₆]³⁻

✅ Answer:
English: A
Hindi: A

Explanation (English):
Exchange of SO₄²⁻ and Br⁻ causes ionisation isomerism.

Q7. The shape of is:

की आकृति है —

A. Square planar / वर्ग समतलीय
B. Tetrahedral / चतुष्फलकीय
C. Octahedral / अष्टफलकीय
D. Linear / रेखीय

✅ Answer:
English: B. Tetrahedral
Hindi: B. चतुष्फलकीय

Explanation (English):
Nickel forms sp³ hybridisation in this complex.

Q8. Which of the following is a chelating ligand?

निम्न में से कौन-सा chelating लिगैंड है?

A. NH₃
B. H₂O
C. EDTA⁴⁻
D. Cl⁻

✅ Answer:
English: C. EDTA⁴⁻
Hindi: C. EDTA⁴⁻

Explanation (English):
EDTA forms multiple bonds with a metal ion.

Q9. Cis–trans isomerism is possible in:

Cis–trans समावयवता पाई जाती है —

A. Tetrahedral complexes
B. Linear complexes
C. Square planar complexes
D. All complexes

✅ Answer:
English: C. Square planar complexes
Hindi: C. वर्ग समतलीय संकुल

Explanation (English):
Different relative positions of ligands cause cis–trans isomerism.

Q10. The colour of coordination compounds is mainly due to:

समन्वय यौगिकों का रंग मुख्यतः किस कारण होता है?

A. Nuclear transition
B. d–d transition
C. f–f transition
D. Charge on ion

✅ Answer:
English: B. d–d transition
Hindi: B. d–d संक्रमण

Explanation (English):
Absorption of visible light promotes electrons between d-orbitals.

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📘 Chapter 5 – Coordination Compounds (NCERT Class 12)

MCQ | 0.5 mark each
Knowledge based
Question & options: English + Hindi
Answer: English + Hindi
Explanation: English only

🔢 MCQs (11–50)

Q11. Which of the following ligands is neutral?

निम्न में से कौन-सा लिगैंड उदासीन (neutral) है?

A. CN⁻ / सायनाइड
B. NH₃ / अमोनिया
C. OH⁻ / हाइड्रॉक्साइड
D. Cl⁻ / क्लोराइड

✅ Answer:
English: B. NH₃
Hindi: B. NH₃

Explanation (English):
NH₃ has no charge and donates a lone pair.

Q12. Coordination number of central metal ion in octahedral complexes is:

अष्टफलकीय संकुलों में केंद्रीय धातु आयन की समन्वय संख्या होती है —

A. 2 / दो
B. 4 / चार
C. 6 / छह
D. 8 / आठ

✅ Answer:
English: C. 6
Hindi: C. छह

Explanation (English):
Octahedral geometry always has six ligands.

Q13. Which complex is diamagnetic?

निम्न में से कौन-सा संकुल डायमैग्नेटिक है?

A. [Fe(H₂O)₆]²⁺
B. [Ni(CO)₄]
C. [CoF₆]³⁻
D. [Mn(H₂O)₆]²⁺

✅ Answer:
English: B. [Ni(CO)₄]
Hindi: B. [Ni(CO)₄]

Explanation (English):
All electrons are paired in [Ni(CO)₄].

Q14. Which ligand forms ring structures with metal ions?

कौन-सा लिगैंड धातु आयन के साथ वलय (ring) बनाता है?

A. Monodentate ligand
B. Ambidentate ligand
C. Chelating ligand
D. Bridging ligand

✅ Answer:
English: C. Chelating ligand
Hindi: C. Chelating ligand

Explanation (English):
Chelating ligands bind through multiple donor atoms forming rings.

Q15. Which of the following shows linkage isomerism?

कौन-सा संकुल linkage समावयवता दर्शाता है?

A. [Co(NH₃)₅Cl]Cl₂
B. [Co(NH₃)₅NO₂]Cl₂
C. [Pt(NH₃)₂Cl₂]
D. [Ni(CO)₄]

✅ Answer:
English: B
Hindi: B

Explanation (English):
NO₂⁻ can bind through N or O, causing linkage isomerism.

Q16. Which metal ion generally forms square planar complexes?

कौन-सा धातु आयन सामान्यतः वर्ग समतलीय संकुल बनाता है?

A. Zn²⁺
B. Cu²⁺
C. Ni²⁺
D. Fe³⁺

✅ Answer:
English: C. Ni²⁺
Hindi: C. Ni²⁺

Explanation (English):
d⁸ metal ions like Ni²⁺ often form square planar complexes.

Q17. Which complex shows optical isomerism?

कौन-सा संकुल प्रकाशीय समावयवता दर्शाता है?

A. [Pt(NH₃)₂Cl₂]
B. [Co(en)₃]³⁺
C. [Ni(CO)₄]
D. [Fe(CN)₆]³⁻

✅ Answer:
English: B
Hindi: B

Explanation (English):
[Co(en)₃]³⁺ is chiral and shows optical isomerism.

Q18. Which ligand is bidentate?

कौन-सा लिगैंड द्विदन्त (bidentate) है?

A. NH₃
B. en
C. Cl⁻
D. H₂O

✅ Answer:
English: B. en
Hindi: B. en

Explanation (English):
Ethylenediamine has two donor nitrogen atoms.

Q19. The oxidation state of Co in is:

में Co की ऑक्सीकरण अवस्था है —

A. +1
B. +2
C. +3
D. 0

✅ Answer:
English: C. +3
Hindi: C. +3

Explanation (English):
NH₃ is neutral; three Cl⁻ balance +3 charge.

Q20. Which of the following is an ambidentate ligand?

निम्न में से कौन-सा ambidentate लिगैंड है?

A. NH₃
B. SCN⁻
C. OH⁻
D. H₂O

✅ Answer:
English: B. SCN⁻
Hindi: B. SCN⁻

Explanation (English):
SCN⁻ can bind through sulfur or nitrogen.

Q21. Which complex has coordination number 4?

किस संकुल की समन्वय संख्या 4 है?

A. [Fe(CN)₆]³⁻
B. [Co(NH₃)₆]³⁺
C. [Pt(NH₃)₂Cl₂]
D. [Cr(H₂O)₆]³⁺

✅ Answer:
English: C
Hindi: C

Explanation (English):
Pt complex has two NH₃ and two Cl⁻ ligands.

Q22. Which theory explains bonding in coordination compounds?

समन्वय यौगिकों में बन्धन किस सिद्धान्त से समझाया जाता है?

A. Valence bond theory
B. Werner theory
C. Kinetic theory
D. Molecular orbital theory

✅ Answer:
English: A
Hindi: A

Explanation (English):
VBT explains hybridisation and magnetic properties.

Q23. The ligand field splitting is maximum in:

लिगैंड क्षेत्र विभाजन सर्वाधिक होता है —

A. Weak field ligands
B. Strong field ligands
C. Neutral ligands
D. Monodentate ligands

✅ Answer:
English: B
Hindi: B

Explanation (English):
Strong field ligands cause greater d-orbital splitting.

Q24. Which complex is inner orbital complex?

कौन-सा संकुल आंतरिक कक्षक (inner orbital) संकुल है?

A. [FeF₆]³⁻
B. [CoF₆]³⁻
C. [Co(NH₃)₆]³⁺
D. [MnF₆]³⁻

✅ Answer:
English: C
Hindi: C

Explanation (English):
NH₃ is strong field → pairing → inner orbital complex.

Q25. Which compound does not ionise in solution?

कौन-सा यौगिक विलयन में आयनित नहीं होता?

A. K₄[Fe(CN)₆]
B. [Ni(CO)₄]
C. [Co(NH₃)₆]Cl₃
D. Na₃[CoF₆]

✅ Answer:
English: B
Hindi: B

Explanation (English):
[Ni(CO)₄] is neutral.

Q26. Which of the following is a strong field ligand?

निम्न में से कौन-सा strong field लिगैंड है?

A. F⁻ / फ्लोराइड
B. Cl⁻ / क्लोराइड
C. CN⁻ / सायनाइड
D. OH⁻ / हाइड्रॉक्साइड

✅ Answer:
English: C. CN⁻
Hindi: C. CN⁻

Explanation (English):
CN⁻ causes large crystal field splitting and electron pairing.

Q27. Which complex shows coordination isomerism?

कौन-सा संकुल समन्वय समावयवता दर्शाता है?

A. [Co(NH₃)₆]Cl₃
B. [Cr(NH₃)₆][Co(CN)₆]
C. [Pt(NH₃)₂Cl₂]
D. [Ni(CO)₄]

✅ Answer:
English: B
Hindi: B

Explanation (English):
Exchange of ligands between cationic and anionic complexes causes coordination isomerism.

Q28. Which geometry is shown by coordination number 2?

समन्वय संख्या 2 किस ज्यामिति को दर्शाती है?

A. Tetrahedral / चतुष्फलकीय
B. Linear / रेखीय
C. Square planar / वर्ग समतलीय
D. Octahedral / अष्टफलकीय

✅ Answer:
English: B. Linear
Hindi: B. रेखीय

Explanation (English):
Two ligands arrange linearly around the metal ion.

Q29. Which of the following is a bridging ligand?

निम्न में से कौन-सा bridging लिगैंड है?

A. NH₃
B. OH⁻
C. CO
D. en

✅ Answer:
English: B. OH⁻
Hindi: B. OH⁻

Explanation (English):
OH⁻ can connect two metal ions simultaneously.

Q30. The oxidation state of chromium in is:

में क्रोमियम की ऑक्सीकरण अवस्था है —

A. +1
B. +2
C. +3
D. +6

✅ Answer:
English: C. +3
Hindi: C. +3

Explanation (English):
Three Cl⁻ ions balance +3 charge on chromium.

Q31. Which complex is outer orbital complex?

कौन-सा संकुल बाह्य कक्षक (outer orbital) संकुल है?

A. [Co(NH₃)₆]³⁺
B. [Fe(CN)₆]⁴⁻
C. [FeF₆]³⁻
D. [Ni(CO)₄]

✅ Answer:
English: C
Hindi: C

Explanation (English):
F⁻ is weak field ligand → no pairing → outer orbital complex.

Q32. Which of the following ligands is polydentate?

निम्न में से कौन-सा बहुदन्त (polydentate) लिगैंड है?

A. NH₃
B. en
C. EDTA⁴⁻
D. H₂O

✅ Answer:
English: C. EDTA⁴⁻
Hindi: C. EDTA⁴⁻

Explanation (English):
EDTA has six donor atoms.

Q33. Which complex shows geometrical isomerism?

कौन-सा संकुल ज्यामितीय समावयवता दर्शाता है?

A. [Ni(CO)₄]
B. [Pt(NH₃)₂Cl₂]
C. [Co(NH₃)₆]³⁺
D. [Fe(CN)₆]³⁻

✅ Answer:
English: B
Hindi: B

Explanation (English):
Square planar complexes show cis–trans isomerism.

Q34. What is the coordination number of Fe in ?

में Fe की समन्वय संख्या है —

A. 3
B. 4
C. 5
D. 6

✅ Answer:
English: D. 6
Hindi: D. छह

Explanation (English):
Six CN⁻ ligands are attached to Fe.

Q35. Which metal ion commonly forms octahedral complexes?

कौन-सा धातु आयन सामान्यतः अष्टफलकीय संकुल बनाता है?

A. Ag⁺
B. Cu²⁺
C. Fe³⁺
D. Zn²⁺

✅ Answer:
English: C. Fe³⁺
Hindi: C. Fe³⁺

Explanation (English):
Fe³⁺ commonly forms coordination number 6 complexes.

Q36. Which ligand causes maximum pairing of electrons?

कौन-सा लिगैंड इलेक्ट्रॉनों का अधिकतम युग्मन कराता है?

A. F⁻
B. Cl⁻
C. CN⁻
D. Br⁻

✅ Answer:
English: C. CN⁻
Hindi: C. CN⁻

Explanation (English):
Strong field ligands force electron pairing.

Q37. The shape of is:

की आकृति है —

A. Linear
B. Square planar
C. Tetrahedral
D. Octahedral

✅ Answer:
English: D. Octahedral
Hindi: D. अष्टफलकीय

Explanation (English):
Three bidentate ligands occupy six coordination sites.

Q38. Which complex ion is paramagnetic?

कौन-सा संकुल आयन पैरामैग्नेटिक है?

A. [Zn(NH₃)₄]²⁺
B. [Ni(CO)₄]
C. [Fe(H₂O)₆]²⁺
D. [Pt(NH₃)₄]²⁺

✅ Answer:
English: C
Hindi: C

Explanation (English):
Unpaired electrons present in Fe²⁺ aqua complex.

Q39. Which ligand donates lone pair through oxygen only?

कौन-सा लिगैंड केवल ऑक्सीजन द्वारा lone pair देता है?

A. NO₂⁻
B. H₂O
C. CN⁻
D. SCN⁻

✅ Answer:
English: B. H₂O
Hindi: B. H₂O

Explanation (English):
Water donates electrons via oxygen atom.

Q40. Which is an example of inner orbital complex?

आंतरिक कक्षक संकुल का उदाहरण कौन-सा है?

A. [FeF₆]³⁻
B. [Co(NH₃)₆]³⁺
C. [MnF₆]³⁻
D. [CrF₆]³⁻

✅ Answer:
English: B
Hindi: B

Explanation (English):
NH₃ causes pairing leading to inner orbital complex.

Q41. Which metal shows maximum oxidation states?

कौन-सी धातु अधिकतम ऑक्सीकरण अवस्थाएँ दर्शाती है?

A. Fe
B. Mn
C. Co
D. Ni

✅ Answer:
English: B. Mn
Hindi: B. Mn

Explanation (English):
Manganese exhibits oxidation states from +2 to +7.

Q42. Which ligand is π-acceptor?

कौन-सा लिगैंड π-acceptor है?

A. NH₃
B. H₂O
C. CO
D. OH⁻

✅ Answer:
English: C. CO
Hindi: C. CO

Explanation (English):
CO accepts electrons via π-back bonding.

Q43. The IUPAC name of is:

का IUPAC नाम है —

A. Hexaammine cobalt chloride
B. Hexaammine cobalt(III) chloride
C. Ammine cobalt chloride
D. Trichloride cobalt ammine

✅ Answer:
English: B
Hindi: B

Explanation (English):
Oxidation state of Co is +3.

Q44. Which complex does not show optical isomerism?

कौन-सा संकुल प्रकाशीय समावयवता नहीं दर्शाता?

A. [Co(en)₃]³⁺
B. [Cr(ox)₃]³⁻
C. [Pt(NH₃)₂Cl₂]
D. [Ni(en)₃]²⁺

✅ Answer:
English: C
Hindi: C

Explanation (English):
Square planar complexes are not chiral.

Q45. Which of the following is a weak field ligand?

निम्न में से कौन-सा weak field लिगैंड है?

A. CN⁻
B. CO
C. NH₃
D. F⁻

✅ Answer:
English: D. F⁻
Hindi: D. F⁻

Explanation (English):
Fluoride causes minimum splitting.

Q46. Which complex shows fac–mer isomerism?

कौन-सा संकुल fac–mer समावयवता दर्शाता है?

A. [Co(NH₃)₆]³⁺
B. [Co(NH₃)₄Cl₂]⁺
C. [Co(NH₃)₃Cl₃]
D. [Pt(NH₃)₂Cl₂]

✅ Answer:
English: C
Hindi: C

Explanation (English):
fac–mer isomerism occurs in octahedral complexes with three identical ligands.

Q47. Coordination compounds obey which theory for colour?

समन्वय यौगिकों का रंग किस सिद्धान्त से समझाया जाता है?

A. Kinetic theory
B. Crystal field theory
C. Atomic theory
D. Valence theory

✅ Answer:
English: B
Hindi: B

Explanation (English):
Colour arises due to d–d transitions explained by CFT.

Q48. Which ligand is π-donor?

कौन-सा लिगैंड π-donor है?

A. CO
B. CN⁻
C. OH⁻
D. NH₃

✅ Answer:
English: C. OH⁻
Hindi: C. OH⁻

Explanation (English):
OH⁻ donates electrons via π-orbitals.

Q49. The coordination number of metal ion in tetrahedral complex is:

चतुष्फलकीय संकुल में समन्वय संख्या होती है —

A. 2
B. 3
C. 4
D. 6

✅ Answer:
English: C. 4
Hindi: C. चार

Explanation (English):
Four ligands surround the metal ion.

Q50. Which complex is used in photography?

कौन-सा संकुल फोटोग्राफी में प्रयुक्त होता है?

A. [Ag(NH₃)₂]⁺
B. [Fe(CN)₆]³⁻
C. [Cu(NH₃)₄]²⁺
D. [Ni(CO)₄]

✅ Answer:
English: A
Hindi: A

Explanation (English):
[Ag(NH₃)₂]⁺ dissolves AgBr in photographic fixing.