| Post Name | Chemist/Conservation Officer- COIRFED, STATE ARCHIVES |
|---|---|
| Question Paper Code | 110/2025/OL |
| Category Code | 325/2024 |
| Date of Test | 8 October 2025 |
| Exam Type | Online Examination |
| Total Questions | 100 |
1
The reaction of ClF₃ and SbF₅ results in the formation
Answer
A. [ClF₂⁺][SbF₆⁻]
2
The CH₂ species is isolobal with:
Answer
C. (CO)₅Fe
3
Which lanthanide ion forms a coloured aqua complex?
Answer
B. Nd³⁺
4
According to Wade's rules:
Answer
C. Both a nido-clusters
5
The correct order of ionic radius is:
Answer
B. S²⁻>Rb⁺>Sr²⁺>Zn²⁺
6
The styx number of is
Answer
B. 4012
7
Which of the following is not an isoelectronic pair?
Answer
A. and
8
Which is not true for zeolites?
Answer
C. Aluminium-rich systems are hydrophobic
9
The extent of ionization of the three hydrogen halides in acetic acid varies as :
Answer
A. HI > HBr > HCl
10
Which statements accurately describe the associative substitution reactions of octahedral complexes? i. A large positive value of ii. A large negative value of iii. A large negative value of iv A large positive value of
Answer
C. both ii and iii
11
The possible number of microstates corresponding to an electronic configuration having the ground state term is
Answer
B. 210
12
The metal present in Chlorophyll is
Answer
C. Mg
13
Which of the following compounds is an example of an organometallic compound?
Answer
C. Ferrocene
14
The NMR spectra of in isopentane, the resonances of fluorine at temperatures °C are appeared as
Answer
C. Single doublet
15
The electrogenic activity of / pump is due to
Answer
D. The development of negative potential inside the cell
16
What is the typical core structure of a cubane cluster?
Answer
A. Tetrahedral
17
Which of the following complex in which a σ-donor ligand is present with?
Answer
A. W(CH₃)₆
18
What are oxidation states of metal ion in the following complexes? I. II. III. IV. ArPdBr where Ar is aryl
Answer
C. 2, 0, 2, 2
19
Which of the following complexes is significantly showing Jahn-Teller distortion?
Answer
A. [Cu(H₂O)₆]²⁺
20
Which type of metal complexes will exhibit an ESR spectrum?
Answer
B. Paramagnetic complexes
21
Which of the following statements are correct about radioactive equilibrium i. The shorter is the half life period, the more easily the equilibrium state is attained ii. At equilibrium all the radioactive elements disintegrate at the same rate iii. Radioactive equilibrium is reversible iv. Radio equilibrium is irreversible
Answer
B. i, ii and iv
22
Which is the carrier ion in sodium β-alumina solid electrolyte?
Answer
A. Na⁺
23
Coordination number and void volume for the lattice type HCP are
Answer
B. 12 and 26%
24
Which of the following statements are correct about photovoltaic effect. i. light energy is converted to electrical energy and vice-versa using a semiconductor ii. p-n junction semiconductor is used iii. Only n-type semiconductor is used iv. Electrons will migrate towards n-type semiconductor
Answer
C. ii and iv
25
Find out the consequence of the stoichiometric crystal defect known as Frenkel defect
Answer
A. Increase in dielectric constant of the crystal
26
Identify the mixed metal oxide with spinel structure
Answer
C. FeCr₂O₄
27
Compound which is not a metal nitride
Answer
B. NaN₃
28
Identify the element produced by the (α,p) nuclear reaction of ₉F¹⁹
Answer
C. ₁₀Ne²²
29
crystalizes in the triclinic crystal system and has
Answer
D. no plane of symmetry and no axis of symmetry
30
Select a condition for a crystal to be a piezoelectric material
Answer
C. It must lack of centre of symmetry
31
Bicyclo[2.2.2]oct-2-ene is
Answer
B. Structural formula shown in the official source as Option B (bicyclo[2.2.2]oct-2-ene)
32
Which of the following pair is diastereomers? i. and ii. and iii. Maleic acid and fumaric acid
Answer
D. all of the above i, ii and iii
33
Which of the following is aromatic i. ii. iii. iv.
Answer
B. only i, ii and iii
34
Which of the following statement is/are correct about mechanism? i. low concentration of nucleophile favours reaction and high concentration of nucleophile favours reaction mechanism ii. Strong nucleophile favours reaction and weak nucleophile favours reaction mechanism iii. reaction is favoured by polar protic solvent, reaction is favoured by polar aprotic solvent
Answer
A. only ii and iii
35
The reaction is an example of
Answer
B. Wolff Kishner reduction
36
The major product of the following reaction is (pyrrole + CH₃CON(CH₃)₂, POCl₃/Na₂CO₃,H₂O).
Answer
A. 2-acetylpyrrole (structural formula shown)
37
Which statements are correct about nitrene? i. Nitrene exists as a singlet state where the nitrogen atom is sp² hybridised. ii. Nitrene is formed when hydrazoic acid is irradiated with ultraviolet light. iii. π insertion of nitrene into C=C gives aziridine.
Answer
D. all of the above statements i, ii and iii
38
A chemical reaction involves enolizable aldehyde or ketone, secondary amine formaldehyde and catalytic HCl to form product aminoketone. The reaction is called
Answer
C. Mannich reaction
39
Which of the following statement is/are incorrect about the shapiro reaction? i. In this reaction ketone is converted to corresponding alkene ii. Carbocation is the intermediate in shapiro reaction iii. Ketone is first converted to tosylhydrazone iv. Carbondioxide gas is evolved during the reaction
Answer
D. only ii and iv
40
Which of the following reaction gives cyclic ketoester is the final product?
Answer
A. Dieckmann condensation
41
Curtius rearrangement involves the decomposition of
Answer
A. Azides
42
Favorskii rearrangement occurs in
Answer
A. -Haloketones with base
43
selectively reduces
Answer
C. Aldehydes and ketones
44
Clemmensen reduction works under
Answer
A. Acidic conditions
45
In Hammett equation, represents :
Answer
D. Electronic substituent constant
46
Taft equation accounts for :
Answer
A. Steric and polar effects
47
Heck reaction couples :
Answer
D. Aryl halide + alkene
48
Stille coupling involves
Answer
C. Organotin compounds
49
Tebbe reagent converts :
Answer
D. Carbonyl compounds → alkenes
50
Which reagent is used for radical reductions?
Answer
A. Bu₃SnH (tri-n-butyltin hydride)
51
The incorrect statement about the Jablonski diagram is
Answer
C. Phosphorescence occurs from the singlet excited state directly to the singlet ground state
52
Which of the following is a diterpene?
Answer
D. Retinol
53
In the Paternò-Büchi reaction, a carbonyl compound reacts with
Answer
B. An alkene to give an oxetane
54
Which of the following steroids is a glucocorticoid hormone?
Answer
C. Cortisol
55
Which of the following is the correct sequence of steps in rational drug design?
Answer
A. Target identification → Lead identification → Lead optimization → Preclinical studies → Clinical trials
56
Which type of electronic transition is responsible for the strongest absorption in conjugated dienes in UV spectroscopy?
Answer
B. *
57
A molecular ion peak at m/z 72 with a base peak at m/z 43 is most likely due to
Answer
D. Butanone
58
In an IR spectrum, a sharp absorption near 1715 cm⁻¹ is generally assigned to
Answer
A. C=O stretching of a ketone
59
Match the NMR technique with its use : 1. DEPT a. Detects through-space interactions 2. COSY b. Distinguishes CH, , groups 3. HSQC c. Correlation between coupled protons 4. NOE d. Correlates protons with directly bonded carbons Options
Answer
A. 1-b, 2-c, 3-d, 4-a
60
In a DEPT-135 spectrum :
Answer
D. CH and signals appear positive, signals negative
61
Equilibrium constant Kp for the decomposition of one mole of water in the vapour state can be
Answer
A. α^(3/2)P^(1/2)/[(1−α)(2+α)^(1/2)]
62
Which among the following is the correct statement?
Answer
C. Sackur-Tetrode equation expresses the entropy of a monatomic gas in terms of volume, internal energy and the number of particles
63
Total energy predicted by the equipartition principle of a molecule is 6.5 kBT. Which among the following can be the molecule?
Answer
A. CO₂
64
The notation (∂G/∂P)T,nᵢ,nⱼ is equal to
Answer
D. V
65
What is the variance at the congruent melting points of - water system as per the reduced equation of phase rule?
Answer
A. 0
66
Which of the following is not a correct form of Maxwell's relations?
Answer
C. (∂S/∂P)ₜ = (∂V/∂T)ₚ
67
Ionic radii of and are 66 pm and 131 pm respectively. Structure of MgO can be
Answer
D. Sodium chloride structure
68
Which among the following statement in connection with liquid crystals is incorrect?
Answer
B. As pressure is raised, nematic to isotropic transition temperature decreases
69
As per the Van der Waal's equation, expression for critical pressure is
Answer
C. a/(27b²)
70
What is the approximate temperature at which the root mean square velocity of hydrogen becomes equal to that of nitrogen at 7ºC?
Answer
D. –253 °C
71
A solid adsorbs 10 mL of gas at STP. Calculate the surface area of the solid if each N molecule occupies an area of . (Avogadro's number = , Molar volume 22.4 L)
Answer
D. 43.25
72
Which of the following microscopy techniques relies on tunneling current between tip and sample?
Answer
C. STM
73
Match the following catalytic theories/mechanisms : Part A Part B a. Langmiur-Hinshelwood 1. Enzyme-substrate complex formation b. Michaelis-Menten 2. Both reactants absorbed on catalyst surface c. Eley-Rideal 3. One reactant absorbed, other from bulk phase d. Lock-and-key model 4. Substrate fits active site with specificity e. Induced-fit model 5. Active site undergoes conformational change on binding
Answer
A. a-2, b-1, c-3, d-4, e-5
74
Identify the incorrect statement regarding BET adsorption isotherm :
Answer
D. It is valid over the entire range of relative pressures (0
75
The slope of a plot of ln k vs 1/T is −5000 K. What is the activation energy (Ea)?
Answer
B. 41.57 kJ·mol⁻¹
76
The cage effect refers to
Answer
C. The restriction of reactive species by solvent molecules
77
Statement : Auger Electron Spectroscopy (AES) can be used to determine the elemental composition of the top few atomic layers of a solid. Which of the following options is correct?
Answer
A. True, because Auger electrons orginate from surface atoms
78
Match the electroanalytical techniques with its main principle a Potentiometry 1. Potential measurement without current flow b. Polarography 2. Measurement of current at a fixed applied potential c. Coulometry 3. Analysis based on the total charge passed during electrolysis d. Cyclic voltamettry 4. Study of reversible/irreversible redox mechanism via potential sweeps e. Conductometry 5. Measurement of conductivity changes during a reaction f. Amperometry 6. Diffusion-controlled current at a dropping mercury electrode
Answer
C. a-1, b-6, c-3, d-4, e-5, f-2
79
A colloidal suspension of nanoparticles shows a zeta potential of -35 mV at pH 7. What does this imply and what happens if the pH is adjusted to the isoelectric point (≈pH 6)
Answer
B. The colloid is stable at -35 mV due to strong repulsion; at the isoelctric point, particles aggregate due to loss of charge
80
Match the following equations with the corresponding adsorption isotherms: a. P/[V(P₀−P)] = 1/(VₘC) + [(C−1)/(VₘC)]·P/P₀ — 1. BET; b. θ = KP/(1+KP) — 2. Langmuir; c. log(x/m) = log k + (1/n)log P — 3. Freundlich; d. qₑ = (RT/b)ln(K_T Cₑ) — 4. Temkin; e. ln qₑ = ln qₘ − βε² — 5. Dubinin–Radushkevich.
Answer
A. a-1, b-2, c-3, d-4, e-5
81
The Compton effect is a phenomenon that cannot be explained by classical mechanics. If the scattering angle 90°, what will be the Compton shift (Δλ)?
Answer
A. Δλ=h/mc
82
In quantum mechanics, the commutator of position and momentum operators [x̂,p̂ₓ] will be equal to
Answer
B. iℏ
83
An electron is confined in 1D-box with edge length (a). If edge length is reduced to (a/2), the energy of electron will be
Answer
D. Increased four times
84
Consider the following molecules and ions i. CO ii. NO iii. iv. Which of these species are associated with similar value of their bond order?
Answer
B. only i and iii
85
The ground state term symbols of ferrous ( ) and ferric ( ) ions are respectively
Answer
C. and
86
The Hartree-Fock approach belongs to which of the following computational method?
Answer
D. Ab initio
87
According to Kopp's law, the molecular heat capacity of a solid compound is approximately equal to
Answer
B. Sum of atomic heat capacities of constituent elements
88
Which of the following statements are incorrect? i. The number of irreducible representations equals the number of classes ii. Irreducible representations are not orthogonal to each other iii. The total number of symmetry operations in the group is called the order of the group iv. All groups not include a totally symmetric representation
Answer
A. only ii and iv
89
The most populated rotational level (Jmax) of a rigid diatomic molecule is related to absolute temperature (T) as
Answer
C. Jmax∝√T
90
In the rotation-vibration spectrum of a diatomic molecule, the P-branch and R-branch lines corresponding to
Answer
D. ΔJ=-1 and ΔJ=+1 respectively
91
What is the result of 13.11+0.3, rounded to the correct number of significant figures?
Answer
A. 13.4
92
In a thermochemical experiment, the enthalpy of neutralization of a strong acid and a strong base is approximately
Answer
B. –57.3 kJ/mol
93
In reverse-phase HPLC, the stationary phase is
Answer
C. Non-polar
94
Ionic liquids are considered green solvents mainly because they
Answer
D. Are non-volatile and recyclable
95
Which nanomaterial is used in sunscreens due to its UV-Blocking ability?
Answer
B. Zinc oxide nanoparticles
96
In green synthesis of nanoparticles, which of the following components in plant extract often acts as a reducing agent?
Answer
C. Polyphenols
97
Piezoelectric sensors convert
Answer
A. Mechanical signals into electrical signal
98
Cyclophanes are important in supramolecular chemistry because
Answer
D. They serve as hosts for guest molecules due to their cavity-like structure
99
The elution of proteins in ion exchange chromatography is typically achieved by
Answer
B. Increasing salt concentration or changing pH
100
Which of the following is a common type of phase transfer catalyst?
Answer
A. Crown ethers
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