CUET UG Chemistry Booster Test - 2 Fundamentals
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QUESTION 1 OF 20
The structural difference between a double salt and a coordination complex is that:
QUESTION 2 OF 20
Consider the following statements regarding the analytical and industrial importance of coordination compounds. Choose the correct statements:
1. Hardness of water is estimated by titration with Na₂EDTA.
2. Ca²⁺ and Mg²⁺ form unstable complexes with EDTA.
3. Extraction of silver and gold makes use of complex formation.
4. Hypo solution dissolves AgBr to form the complex ion [Ag(S₂O₃)₂]³⁻.
QUESTION 3 OF 20
Identify the chemical reaction process used for the purification of nickel:
QUESTION 4 OF 20
Match the catalyst/reagent (List I) with its specific biological or medical role (List II):
| List I | List II |
|---|---|
| 1. Vitamin B₁₂ | a. Treatment of lead poisoning |
| 2. EDTA | b. Removal of excess copper and iron |
| 3. Cis-platin | c. Anti-pernicious anaemia factor |
| 4. D-penicillamine | d. Inhibition of tumour gr |
QUESTION 5 OF 20
The modern formulation of Werner's spatial arrangements for secondary linkages is known as:
QUESTION 6 OF 20
The numerical value of the primary valence of the central metal ion in the complex [Co(NH₃)₅Cl]Cl₂ is:
QUESTION 7 OF 20
According to the passage and Werner's experimental observations, if a complex has the completely intact formulation [CoCl₃(NH₃)₃], how many moles of AgCl will precipitate upon adding excess aqueous AgNO₃?
QUESTION 8 OF 20
Based on the passage, the complex [CoCl₃(NH₃)₃] in an aqueous solution will behaviorally act as a:
QUESTION 9 OF 20
The IUPAC name of the complex K₂[PdCl₄] is:
QUESTION 10 OF 20
Arrange the following entities in decreasing order of the number of counter ions present:
1. K₄[Fe(CN)₆]
2. [Co(NH₃)₆]Cl₃
3. K₂[PdCl₄]
4. [Ni(CO)₄]
QUESTION 11 OF 20
In the coordination entity [Fe(CN)₆]³⁻, the metal center acts as the:
QUESTION 12 OF 20
Consider the following statements regarding central metal ions. Choose the correct statements:
1. They accept electron pairs from ligands.
2. They are referred to as Lewis acids.
3. They are referred to as Lewis bases.
4. Complexes where the metal is bound to more than one kind of donor group are heteroleptic.
QUESTION 13 OF 20
What structural type of ligand is the ethylenediaminetetraacetate ion (EDTA⁴⁻)?
QUESTION 14 OF 20
Arrange the following ligands in decreasing order of their field strength based on the spectrochemical series:
1. CO
2. NH₃
3. H₂O
4. I⁻
QUESTION 15 OF 20
When a ligand is bound to a metal ion through a single donor atom, it is called unidentate. Which of the following is NOT a unidentate ligand?
QUESTION 16 OF 20
The IUPAC name of the polydentate-containing complex [Co(H₂NCH₂CH₂NH₂)₃]₂(SO₄)₃ is:
QUESTION 17 OF 20
The number of ligating groups used by a di- or polydentate ligand simultaneously to bind a single metal ion and form a ring is explicitly called its:
QUESTION 18 OF 20
Which of the following statements about the chelate effect is/are correct?
1. Chelate complexes are more stable than similar complexes with unidentate ligands.
2. The presence of a chelating ligand decreases overall complex stability.
3. Didentate and polydentate ligands form stable chelate rings.
4. Ambidentate ligands always form chelate complexes.
QUESTION 19 OF 20
Ambidentate ligands possessing dual sites can uniquely lead to which structural isomerism type in coordination compounds?
QUESTION 20 OF 20
Match the bound complex (List I) with its IUPAC naming convention for the ambidentate ligand (List II):
| List I | List II |
|---|---|
| 1. M–NO₂ | a. thiocyanato-S |
| 2. M–ONO | b. nitrito-O |
| 3. M–SCN | c. thiocyanato-N |
| 4. M–NCS | d. nitrito-N |
Test Complete!
Answer Review
1 The structural difference between a double salt and a coordination complex is that:
�� Double salts dissociate completely in water. �� Complex ions remain intact in solution. �� Coordination sphere is preserved.
Double salts such as Mohr's salt dissociate completely into constituent ions in aqueous solution. However, coordination compounds produce complex ions that remain intact and do not dissociate into simple metal ions and ligands. For example, [Fe(CN)₆]⁴⁻ remains as a coordination entity in solution.
- �� Option A → Double salts do dissociate completely.
- �� Option B → Complex ions remain intact.
- �� Option D → Only double salts dissociate completely into simple ions.
Used
- Odd One Out
Application:
- Compare the behavior of double salts and coordination compounds in water.
Final Logic:
- Complex ions remain intact whereas double salts dissociate completely.
Double Salt Breaks, Complex Stays
2 Consider the following statements regarding the analytical and industrial importance of coordination compounds. Choose the correct statements:
1. Hardness of water is estimated by titration with Na₂EDTA.
2. Ca²⁺ and Mg²⁺ form unstable complexes with EDTA.
3. Extraction of silver and gold makes use of complex formation.
4. Hypo solution dissolves AgBr to form the complex ion [Ag(S₂O₃)₂]³⁻.
�� EDTA is used in hardness determination. �� Gold and silver extraction use complex formation. �� Hypo forms a soluble silver-thiosulphate complex.
Statement 1 is correct because EDTA titration is used to estimate water hardness. Statement 3 is correct because cyanide complex formation is employed in gold and silver extraction. Statement 4 is correct because AgBr dissolves in hypo (Na₂S₂O₃) forming [Ag(S₂O₃)₂]³⁻. Statement 2 is incorrect because Ca²⁺ and Mg²⁺ form stable complexes with EDTA.
- �� Statement 2 → EDTA forms stable chelates with Ca²⁺ and Mg²⁺.
- �� Option A → Contains incorrect Statement 2.
- �� Option C → Contains incorrect Statement 2.
- �� Option D → Contains incorrect Statement 2.
Used
- Option Grouping
Application:
- Evaluate Statements 1, 2, 3 and 4 independently.
Final Logic:
- Only Statements 1, 3 and 4 are correct.
EDTA Measures Hardness
3 Identify the chemical reaction process used for the purification of nickel:
�� Mond process purifies nickel. �� Volatile nickel carbonyl is formed. �� Thermal decomposition yields pure nickel.
In Mond's process, impure nickel reacts with carbon monoxide to form volatile Ni(CO)₄. This compound is then heated to decompose it into pure nickel and carbon monoxide. Ni + 4CO → Ni(CO)₄ Ni(CO)₄ → Ni + 4CO Therefore Option A is correct.
- �� Option B → Not used for nickel purification.
- �� Option C → EDTA is not employed for nickel refining.
- �� Option D → Wilkinson catalyst is used for alkene hydrogenation.
Used
- Conceptual Recall
Application:
- Recall industrial applications of coordination compounds.
Final Logic:
- Nickel purification occurs through the Mond process.
Mond = Nickel Carbonyl
4 Match the catalyst/reagent (List I) with its specific biological or medical role (List II):
| List I | List II |
|---|---|
| 1. Vitamin B₁₂ | a. Treatment of lead poisoning |
| 2. EDTA | b. Removal of excess copper and iron |
| 3. Cis-platin | c. Anti-pernicious anaemia factor |
| 4. D-penicillamine | d. Inhibition of tumour gr |
�� Vitamin B₁₂ treats pernicious anaemia. �� EDTA removes toxic metals. �� Cis-platin is an anticancer drug.
1 → c : Vitamin B₁₂ is an anti-pernicious anaemia factor. 2 → a : EDTA is used in lead poisoning treatment. 3 → d : Cis-platin inhibits tumour growth. 4 → b : D-penicillamine removes excess copper and iron. Thus the correct matching is 1-c, 2-a, 3-d, 4-b.
- �� Option B → Incorrect matching of Vitamin B₁₂ and EDTA.
- �� Option C → Incorrect assignment of all major roles.
- �� Option D → Incorrect therapeutic associations.
Used
- Option Grouping
Application:
- Match each compound with its medical application.
Final Logic:
- Only Option A gives all correct pairings.
B₁₂–Anaemia, EDTA–Lead, Cisplatin–Cancer
5 The modern formulation of Werner's spatial arrangements for secondary linkages is known as:
�� Secondary valences determine geometry. �� Ligands occupy definite positions. �� Modern description uses polyhedra.
Werner proposed definite spatial arrangements for secondary valences. In modern coordination chemistry, these geometrical arrangements are described using coordination polyhedra such as octahedral, tetrahedral and square planar structures.
- �� Option A → Refers to oxidation number.
- �� Option C → Related to primary valence.
- �� Option D → Describes ligand field strength.
Used
- Conceptual Recall
Application:
- Relate Werner's theory to modern terminology.
Final Logic:
- Spatial arrangements are described as coordination polyhedra.
Geometry = Polyhedron
6 The numerical value of the primary valence of the central metal ion in the complex [Co(NH₃)₅Cl]Cl₂ is:
�� Primary valence equals oxidation state. �� NH₃ is neutral. �� One coordinated chloride is present.
Let oxidation state of Co = x. x + 5(0) + (−1) = +2 x − 1 = +2 x = +3 According to Werner's theory, primary valence corresponds to oxidation state. Therefore the primary valence is 3.
- �� Option A → Not the oxidation state.
- �� Option C → Represents coordination number.
- �� Option D → Number of NH₃ ligands only.
Used
- Substitution
Application:
- Calculate oxidation state using charge balance.
Final Logic:
- Primary valence = oxidation state = +3.
Primary Valence = Oxidation State
7
According to the passage and Werner's experimental observations, if a complex has the completely intact formulation [CoCl₃(NH₃)₃], how many moles of AgCl will precipitate upon adding excess aqueous AgNO₃?
�� All chloride ions are coordinated. �� No free chloride ions exist. �� AgNO₃ precipitates only free Cl⁻.
In [CoCl₃(NH₃)₃], all three chloride ions are inside the coordination sphere. Since no chloride ions are present outside the coordination sphere, none are available to react with AgNO₃. Therefore no AgCl precipitate is formed.
- �� Option A → Requires three free chloride ions.
- �� Option B → Requires two free chloride ions.
- �� Option C → Requires one free chloride ion.
Used
- Substitution
Application:
- Count chloride ions outside the coordination sphere.
Final Logic:
- No free chloride ions means no AgCl precipitate.
Inside Bracket = No AgCl
8
Based on the passage, the complex [CoCl₃(NH₃)₃] in an aqueous solution will behaviorally act as a:
�� Entire species remains neutral. �� No counter ions are present. �� No ions are produced in solution.
The coordination entity [CoCl₃(NH₃)₃] is electrically neutral and contains no ionisable chloride ions outside the coordination sphere. Therefore it does not produce ions in solution and behaves as a non-electrolyte.
- �� Option A → Requires four ions in solution.
- �� Option B → Requires three ions in solution.
- �� Option C → Requires two ions in solution.
Used
- Elimination
Application:
- Check whether ionisable ions exist outside the coordination sphere.
Final Logic:
- No ionisation implies non-electrolytic behavior.
No Counter Ion = Non-Electrolyte
9 The IUPAC name of the complex K₂[PdCl₄] is:
�� Complex ion is anionic. �� Palladium oxidation state is +2. �� Anionic metal names end with "-ate".
For [PdCl₄]²⁻: x + 4(−1) = −2 x = +2 Since the complex ion is negatively charged, palladium becomes palladate. Therefore the correct name is Potassium tetrachloridopalladate(II).
- �� Option A → Used for neutral/cationic complexes.
- �� Option C → Palladium oxidation state is +2, not +4.
- �� Option D → Prefix "di" is not used for counter ions.
Used
- Substitution
Application:
- Calculate oxidation state and identify anionic complex naming.
Final Logic:
- Anionic Pd complex → palladate(II).
Negative Complex → -ate
10 Arrange the following entities in decreasing order of the number of counter ions present:
1. K₄[Fe(CN)₆]
2. [Co(NH₃)₆]Cl₃
3. K₂[PdCl₄]
4. [Ni(CO)₄]
�� Count ions outside the coordination sphere. �� K⁺ and Cl⁻ act as counter ions. �� Neutral complexes have none.
1. K₄[Fe(CN)₆] → 4 counter ions (4 K⁺) 2. [Co(NH₃)₆]Cl₃ → 3 counter ions (3 Cl⁻) 3. K₂[PdCl₄] → 2 counter ions (2 K⁺) 4. [Ni(CO)₄] → 0 counter ions Decreasing order: 1 > 2 > 3 > 4
- �� Option B → Places 3 counter ions above 4 counter ions.
- �� Option C → Places 2 counter ions above 3 counter ions.
- �� Option D → Completely reversed order.
Used
- Option Grouping
Application:
- Count counter ions present outside the coordination sphere.
Final Logic:
- 4 > 3 > 2 > 0.
Count Outside-Bracket Ions
11 In the coordination entity [Fe(CN)₆]³⁻, the metal center acts as the:
�� CN⁻ has a charge of −1. �� Six CN⁻ ligands contribute −6 charge. �� Overall charge is −3.
Let oxidation state of Fe = x. x + 6(−1) = −3 x − 6 = −3 x = +3 Therefore the central metal ion present in the coordination entity is Fe³⁺.
- �� Option A → Fe²⁺ would give an overall charge of −4.
- �� Option C → CN⁻ is the ligand, not the metal center.
- �� Option D → Iron is not present in the neutral state.
Used
- Substitution
Application:
- Calculate oxidation number using overall charge.
Final Logic:
- Fe oxidation state is +3.
−6 + Fe = −3 ⇒ Fe = +3
12 Consider the following statements regarding central metal ions. Choose the correct statements:
1. They accept electron pairs from ligands.
2. They are referred to as Lewis acids.
3. They are referred to as Lewis bases.
4. Complexes where the metal is bound to more than one kind of donor group are heteroleptic.
�� Metal ions accept electron pairs. �� Electron-pair acceptors are Lewis acids. �� Different ligands form heteroleptic complexes.
Statement 1 is correct because metal ions accept lone pairs from ligands. Statement 2 is correct because electron-pair acceptors are Lewis acids. Statement 4 is correct because complexes containing more than one kind of ligand are called heteroleptic complexes. Statement 3 is incorrect because the metal ion acts as a Lewis acid, not a Lewis base.
- �� Statement 3 → Lewis bases donate electron pairs; metal ions accept them.
- �� Option B → Contains incorrect Statement 3.
- �� Option C → Contains incorrect Statement 3.
- �� Option D → Omits correct Statement 4.
Used
- Option Grouping
Application:
- Evaluate Statements 1, 2, 3 and 4 separately.
Final Logic:
- Statements 1, 2 and 4 are correct.
Metal Accepts → Acid; Mixed Ligands → Heteroleptic
13 What structural type of ligand is the ethylenediaminetetraacetate ion (EDTA⁴⁻)?
�� EDTA contains six donor atoms. �� Forms multiple coordinate bonds. �� Produces highly stable chelates.
EDTA⁴⁻ coordinates through six donor atoms (two nitrogen atoms and four oxygen atoms). Therefore it is classified as a hexadentate ligand.
- �� Option A → Contains only one donor atom.
- �� Option B → Contains two donor atoms.
- �� Option C → Contains four donor atoms.
Used
- Conceptual Recall
Application:
- Recall denticity of common ligands.
Final Logic:
- EDTA possesses six donor sites.
EDTA = 6 Hands
14 Arrange the following ligands in decreasing order of their field strength based on the spectrochemical series:
1. CO
2. NH₃
3. H₂O
4. I⁻
�� CO is a strong-field ligand. �� NH₃ is stronger than H₂O. �� I⁻ is a weak-field ligand.
From the spectrochemical series: CO > NH₃ > H₂O > I⁻ CO produces the largest crystal field splitting, while iodide is among the weakest field ligands. Therefore the decreasing order is: CO > NH₃ > H₂O > I⁻
- �� Option B → Completely reversed order.
- �� Option C → Places H₂O above NH₃ incorrectly.
- �� Option D → Places NH₃ above CO incorrectly.
Used
- Conceptual Recall
Application:
- Recall the spectrochemical series.
Final Logic:
- CO is strongest and I⁻ is weakest.
CO > NH₃ > H₂O > I⁻
15 When a ligand is bound to a metal ion through a single donor atom, it is called unidentate. Which of the following is NOT a unidentate ligand?
�� Oxalate contains two donor oxygen atoms. �� It binds through both simultaneously. �� Therefore it is bidentate.
Oxalate ion (C₂O₄²⁻) coordinates through two oxygen donor atoms and forms chelate rings. Hence it is a bidentate ligand and not a unidentate ligand.
- �� Option A → Cl⁻ has one donor atom.
- �� Option B → H₂O coordinates through one oxygen atom.
- �� Option D → NH₃ coordinates through one nitrogen atom.
Used
- Odd One Out
Application:
- Identify the ligand with more than one donor atom.
Final Logic:
- Oxalate is the only bidentate ligand listed.
Oxalate = Two Oxygens = Bidentate
16 The IUPAC name of the polydentate-containing complex [Co(H₂NCH₂CH₂NH₂)₃]₂(SO₄)₃ is:
�� Ethane-1,2-diamine is neutral. �� Sulphate is the counter ion. �� Cobalt oxidation state is +3.
The complex cation is: [Co(en)₃]³⁺ where en = ethane-1,2-diamine. Since sulphate ions balance the charge: 2(+3) + 3(−2) = 0 The oxidation state of cobalt is +3. Therefore the IUPAC name is Tris(ethane-1,2-diamine)cobalt(III) sulphate.
- �� Option B → Oxidation state is not +2.
- �� Option C → Incorrect naming convention for the salt.
- �� Option D → "Cobaltate" is used for anionic complexes.
Used
- Substitution
Application:
- Determine oxidation state and identify the complex cation.
Final Logic:
- Neutral ligand en gives Co oxidation state +3.
en Neutral → Co = +3
17 The number of ligating groups used by a di- or polydentate ligand simultaneously to bind a single metal ion and form a ring is explicitly called its:
�� Denticity counts donor atoms. �� Determines ligand binding capacity. �� Important in chelation.
Denticity refers to the number of donor atoms of a ligand that simultaneously coordinate to the same metal ion. It determines whether a ligand is unidentate, bidentate, tetradentate, hexadentate, etc.
- �� Option A → Refers to Werner's primary valence.
- �� Option B → Indicates oxidation state.
- �� Option D → Refers to the total number of coordinate bonds around the metal.
Used
- Conceptual Recall
Application:
- Recall the definition of denticity.
Final Logic:
- Denticity equals the number of coordinating donor atoms.
Denticity = Number of Teeth (Donors)
18 Which of the following statements about the chelate effect is/are correct?
1. Chelate complexes are more stable than similar complexes with unidentate ligands.
2. The presence of a chelating ligand decreases overall complex stability.
3. Didentate and polydentate ligands form stable chelate rings.
4. Ambidentate ligands always form chelate complexes.
�� Chelate effect increases stability. �� Multidentate ligands form rings. �� Ambidentate ligands need not form chelates.
Statement 1 is correct because chelate complexes are generally more stable than analogous complexes containing unidentate ligands. Statement 3 is correct because di- and polydentate ligands form stable chelate rings. Statement 2 is incorrect because chelation increases stability. Statement 4 is incorrect because ambidentate ligands coordinate through only one donor atom at a time and do not necessarily form chelates.
- �� Statement 2 → Opposite of the chelate effect.
- �� Statement 4 → Ambidentate ligands do not always form chelate rings.
- �� Option B → Contains incorrect Statements 2 and 4.
- �� Option C → Contains incorrect Statement 2.
- �� Option D → Contains incorrect Statement 4.
Used
- Option Grouping
Application:
- Evaluate Statements 1, 2, 3 and 4 separately.
Final Logic:
- Only Statements 1 and 3 are correct.
Chelate Ring = Greater Stability
19 Ambidentate ligands possessing dual sites can uniquely lead to which structural isomerism type in coordination compounds?
�� Ambidentate ligands have two donor atoms. �� Coordination can occur through either donor atom. �� Different attachment modes create isomers.
Ambidentate ligands such as NO₂⁻ and SCN⁻ can coordinate through different donor atoms. This results in compounds having the same composition but different points of attachment, producing linkage isomerism.
- �� Option A → Depends on ligand arrangement in space.
- �� Option B → Depends on chirality.
- �� Option D → Involves exchange between complex cation and anion.
Used
- Conceptual Recall
Application:
- Recall the special isomerism associated with ambidentate ligands.
Final Logic:
- Alternative donor atoms lead to linkage isomerism.
Ambidentate → Linkage Isomer
20 Match the bound complex (List I) with its IUPAC naming convention for the ambidentate ligand (List II):
| List I | List II |
|---|---|
| 1. M–NO₂ | a. thiocyanato-S |
| 2. M–ONO | b. nitrito-O |
| 3. M–SCN | c. thiocyanato-N |
| 4. M–NCS | d. nitrito-N |
�� NO₂ indicates N-bonding. �� ONO indicates O-bonding. �� SCN and NCS specify donor atoms directly.
1 → d : M–NO₂ = nitrito-N 2 → b : M–ONO = nitrito-O 3 → a : M–SCN = thiocyanato-S 4 → c : M–NCS = thiocyanato-N Thus the correct matching is 1-d, 2-b, 3-a, 4-c.
- �� Option B → Reverses nitrito and thiocyanato donor assignments.
- �� Option C → Incorrectly matches ONO and SCN.
- �� Option D → Incorrect assignment of donor atoms.
Used
- Option Grouping
Application:
- Identify the donor atom attached directly to the metal.
Final Logic:
- The atom written adjacent to M indicates the donor atom.
NO₂ → N, ONO → O, SCN → S, NCS → N
