BPSC Exam 2025: Integrated 70th Combined Main (Written) Competitive Examination, Optional, Chemistry
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Serial No.
Booklet Series
02/GO/CC/M-2025 – 08
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I
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Candidate’s Roll Number
Question Booklet
I
CHEMISTRY
Time Allowed : 2 Hours Maximum Marks : 100
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1. Which solvent would best promote an 6. In an SN2 reaction, the rate depends on
SN1 reaction? (A) Both substrate and nucleophile
(A) Diethyl ether concentrations
(B) Dimethyl Sulfoxide (DMSO) (B) Only substrate concentration
(C) Hexane (C) Neither substrate nor nucleophile
concentration
(D) Methanol
(D) Only nucleophile concentration
2. High quantum yields are observed in
7. The liquid junction potential arises due to
(A) Synthesis reactions
(A) No ion movement
(B) Chain reactions (B) Different mobilities of ions
(C) Isomerization reactions (C) Equal concentration of solutions
(D) Simple decomposition reactions (D) Same mobilities of ions
3. In Raman spectroscopy, the Stokes lines 8. Silicones differ from carbon-based
appear at polymers in their
(A) Same frequency as excitation (A) Higher reactivity
(B) Higher frequency than excitation (B) Higher thermal stability
(C) Random frequencies
(D) Lower frequency than excitation (D) Lower molecular weight
9. The actinide contraction is caused by
4. In an adiabatic process
(A) Incomplete shielding of 5d electrons
(A) No heat is exchanged
(B) Incomplete shielding of 5f electrons
(B) Temperature is constant
(C) Incomplete shielding of 6s electrons
(C) No work is done
(D) None of the above
(D) Pressure is constant
10. In valence bond theory, a sigma bond is
5. In 1H NMR, deshielded protons appear formed by
(A) At 0 ppm (A) Perpendicular overlap
(B) Side-by-side overlap
(C) No overlap
(D) End-to-end overlap
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11. The Friedel-Crafts reaction is an 16. In nucleophilic aromatic substitution,
example of which is not a common mechanism ?
(A) Free radical substitution (A) Addition-elimination
(B) Nucleophilic substitution (B) SN1
(C) Elimination reaction
(C) Benzyne
(D) Electrophilic substitution
(D) SRN1
12. The Jahn-Teller effect is observed in 17. According to the collision theory,
(A) High-spin d 9 complexes increasing temperature will
(B) High-spin d 4 complexes (A) Have no effect on the frequency of
(C) Low-spin d 9 complexes effective collisions
(B) Decrease the frequency of effective
(D) Low-spin d 4 complexes
collisions
13. The McLafferty rearrangement in mass (C) Decrease the activation energy
spectrometry involves (D) Increase the frequency of effective
(A) Only carbon-carbon bond cleavage collisions
(B) Simple fragmentation
(C) Only elimination reactions 18. In the Claisen condensation between two
(D) Hydrogen transfer and bond esters, the driving force is
cleavage (A) Formation of a carbanion
(B) Formation of water
14. The rate of a photochemical reaction is (C) Relief of steric strain
proportional to (D) Formation of an alcohol
(A) Both intensity of light and concentration
of reactants 19. The separation of lanthanides is based on
(B) Intensity of light (A) Solvent extraction
(B) Fractional crystallization
(C) Neither intensity of light nor
(C) Ion exchange chromatography
concentration of reactants
(D) All of the above
(D) Concentration of reactants
20. In a concentration cell, the EMF depends
15. The bathochromic shift in conjugated on
systems is due to (A) Both temperature and concentration
(A) Hyperchromic effect ratio
(B) Decreased conjugation (B) Temperature only
(C) Hypochromic effect (C) Pressure only
(D) Increased conjugation (D) Concentration ratio only
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21. The Wagner-Meerwein rearrangement 26.
involves chemistry depends on
(A) Both hydride and alkyl shifts (A) Both molecular weight and shape
(B) Hydride shift (B) Molecular weight only
(C) Neither hydride nor alkyl shifts (C) Neither molecular weight nor shape
(D) Alkyl shift (D) Shape only
22. Which spectroscopic technique is 27. The Onsager limiting law for the molar
most useful for determining molecular conductivity of an electrolyte is valid at
connectivity ? (A) Intermediate concentrations
(A) NMR (B) All concentrations
(B) UV-Visible (C) Low concentrations
(C) Mass spectrometry (D) High concentrations
(D) IR
28. The Reimer-Tiemann reaction is used
23. According to Fajan’s rules, covalent to introduce which functional group to
character increases with phenols ?
(A) Larger cation and smaller anion (A) Amino group
(B) Smaller cation and larger anion (B) Nitro group
(C) Higher charge on cation (C) Sulfonic acid group
(D) Both (B) and (C) (D) Formyl group
24. E2 elimination reactions show 29. The charge transfer transitions in
complexes occur between
(A) Zero-order kinetics
(A) Bonding and antibonding orbitals
(B) First-order kinetics
(B) t2g and eg orbitals
(C) Third-order kinetics
(C) Metal d orbitals and ligand orbitals
(D) Second-order kinetics
(D) None of the above
25. In a photoelectric cell, the photocurrent
depends on 30. The presence of radicals is best detected
by
(A) Intensity of incident light
(A) EPR spectroscopy
(B) Wavelength of incident light
(B) UV spectroscopy
(C) Both (A) and (B)
(C) NMR spectroscopy
(D) Neither (A) nor (B)
(D) IR spectroscopy
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31. Enthalpy of formation of elements in their 36. What determines the intensity of
standard states is vibrational-rotational transitions ?
(A) Both dipole moment and temperature
(B) Unity (B) Only dipole moment
(C) Depends on the element (C) Only temperature
(D) Zero (D) None of the above
32. The nitrogen rule in mass spectrometry 37. In the addition of HBr to propene, the
states that molecules containing major product is
(A) Any nitrogen has even mass (A) Both in equal amounts
(B) An odd number of nitrogen have even (B) 1-bromopropane
mass (C) 2-bromopropane
(C) Any nitrogen has odd mass (D) None of the above
(D) An odd number of nitrogen have odd
mass 38. The metal-metal bond in
[Cr2(CH3COO)4(H2O)2] is best described
33. The reducing strength of metals in liquid
as
ammonia follows the order
(A) Triple bond
(A) Cs < Rb < K < Na < Li
(B) Single bond
(B) Li < Na < K < Rb < Cs
(C) Quadruple bond
(C) Cs > Rb > K > Na > Li
(D) Double bond
(D) Li > Na > K > Rb > Cs
39. The rule of mutual exclusion applies to
34. The Frank-Condon principle explains
(A) Only polar molecules
(A) Electronic transitions
(B) All molecules
(C) Only non-polar molecules
(C) Spin-orbit coupling
(D) Only centrosymmetric molecules
40. Born-Haber cycle is used to calculate
35. Frenkel defect is commonly found in which energy ?
(A) AgCl (A) Ionization enthalpy
(B) NaCl (B) Covalent bond energy
(C) CsCl (C) Electron gain enthalpy
(D) KCI (D) Lattice energy
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41. In the benzyne mechanism, the 46. Polystyrene is produced by
intermediate has (A) Step-growth polymerization
(A) sp3 hybridization
(B) Addition polymerization
(B) sp hybridization
(C) Ring-opening polymerization
(C) Both sp and sp2 hybridization
(D) sp2 hybridization (D) Condensation polymerization
42. N-Bromosuccinimide (NBS) is commonly 47. For an ideal gas, internal energy
used for
(A) Depends on temperature only
(A) Alcohol oxidation
(B) Allylic bromination (B) Depends on volume only
(C) Ketone reduction (C) Depends on both pressure and
(D) Aromatic nitration volume
(D) Depends on pressure only
43. Which crystal system has all sides equal
and all angles 90° ? 48. The number of fundamental vibrational
(A) Monoclinic modes for a linear triatomic molecule is
(B) Triclinic (A) 5
(C) Orthorhombic
(B) 3
(D) Cubic
(C) 6
44. The major product of the Cannizzaro (D) 4
reaction with benzaldehyde is
(A) Benzyl alcohol and benzene 49. The law of rational indices states that
(B) Benzyl alcohol and benzoic acid (A) Indices can be irrational numbers
(C) Two molecules of benzoic acid
(B) All indices must be whole numbers
(D) Benzene and benzoic acid
(C) Indices must be prime numbers
45. The molecularity of a reaction refers to (D) The ratio of indices must be rational
(A) The order of the reaction with numbers
respect to each reactant
(B) The number of bonds broken/formed 50. The Perkin reaction is a method to
prepare which compound ?
in the rate-determining step
(A) -hydroxy acids
(C) The number of elementary steps in
the reaction mechanism (B) -unsaturated acids
(D) The number of reactant molecules (C) -keto esters
that collide to form products (D) -hydroxy aldehydes
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51. The shielding of 4f electrons in 56. The value of G at equilibrium is
lanthanides is due to
(A) Zero
(A) 6s and 6p electrons
(B) Positive
(B) 5s and 5p electrons
(C) Depends on temperature
(C) 4f electrons themselves
(D) Negative
(D) 5d and 6s electrons
57. Which reactive intermediate is sp2
52. Lattice energy generally increases with hybridized with one empty p orbital ?
(A) Decreasing charge on ions (A) Carbanion
(B) Decreasing size of ions (B) Carbene
(C) Increasing size of ions (C) Free radical
(D) None of these (D) Carbocation
53. 58. According to the Debye-Hückel theory,
occurs at
(A) 1250 – 400 cm–1 inversely proportional to
(B) 4000 – 3000 cm–1 (A) The cube root of the ion charge
(C) Above 4000 cm–1
(B) The square root of the ion charge
(D) 3000 – 1250 cm–1
(C) The cube of the ion charge
54. Which of the following is not a (D) The square of the ion charge
characteristics of fuel cells ?
59.
(B) Continuous supply of reactants (A) Electron-nuclear coupling
(C) Single use only (B) Electron-electron coupling
(D) Direct conversion of chemical (C) Spin-orbit coupling
energy to electrical energy
(D) Nuclear-nuclear coupling
55. The Aldol condensation product forms
60. For a particle in a one-dimensional box
via
(A) Initial formation of a free radical (A) All energy level are equally spaced
(B) Initial formation of an enolate (B) Energy is continuous
(C) Initial formation of a carbene (C) Energy is independent of box length
(D) Initial formation of a carbocation (D) Energy is quantized
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61. The high strength of Nylon is primarily 66. Which electronic transition has the
due to highest energy ?
(A) Covalent bonding (A) *
(B) Hydrogen bonding (B) n *
(C) Ionic bonding (C) n *
(D) van der Waals forces (D) *
62. According to the absolute reaction rate 67. The electronic spectra of lanthanide
theory, the rate constant is proportional to complexes exhibit
(A) Concentration
(A) Continuous absorption
(B) Activation energy
(B) Broad bands
(C) Partition function
(D) Pressure (C) No absorption
(D) Sharp lines
63. Which mass analyzer provides the
highest resolution ? 68. According to Kirchhoff’s equation
(A) H varies inversely with temperature
(B) Quadrupole
(C) Fourier transform ion cyclotron (B) H is independent of temperature
resonance (C) H is always constant
(D) Ion trap
(D) H varies with temperature according
64. Which of the following is the strongest to Cp
reducing agent among the lanthanides ?
69. Borazines differ from benzene in
(A) Eu2+
(A) Electronic distribution
(B) Ce3+
(B) Ring size
(C) Yb2+
(C) Number of electrons
(D) Sm2+
(D) Bond angles
65. A Schottky defect in an ionic crystal
70. The EMF of a concentration cell
(A) Creates equal numbers of cation and
anion vacancies (A) Is independent of temperature
(B) Creates only cation vacancies (B) Increases with temperature
(C) Creates interstitial ions
temperature
(D) Creates only anion vacancies
(D) Decreases with temperature
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71. First-order coupling in NMR occurs when 76. The rotational energy levels of a diatomic
(A) Coupling constants are large molecule are
(A) Inversely proportional to J
(B) Chemical shifts are similar
(B) Equally spaced
(C) Coupling constants are small
(C) Independent of J
(D) Chemical shifts are very different (D) Proportional to J (J+1)
72. 77. The stability of the +2 oxidation state in
(A) Independent of the rate constant actinides
(B) Inversely proportional to the rate (A) Remains constant across the series
constant (B) Increases across the series
(C) Proportional to the square root of (C) Varies irregularly across the series
the rate constant (D) Decreases across the series
(D) Directly proportional to the rate
constant 78. The phase of X-ray waves after
diffraction
73. Ziegler-Natta catalysts are used in the (A) Is always zero
synthesis of (B) Can be directly measured
(C) Is always /2
(A) Branched polyethylene
(D) Cannot be directly measured
(B) Isotactic polypropylene
(C) Polyvinyl chloride 79. The g-tensor in ESR becomes
(D) Random copolymers anisotropic due to
(A) Electron spin
74. E1CB mechanisms are most likely when (B) Nuclear spin
(C) Rotation
(A) Strong acid is present
(D) Orbital angular momentum
(B) The leaving group is poor
(C) The -hydrogen is very acidic 80. Which of the following is not a type of
pericyclic reaction ?
(D) The substrate is primary
(A) Sigmatropic rearrangement
75. The Schrödinger wave equation for a (B) Cycloaddition
hydrogen atom (C) Nucleophilic addition
(A) Can be solved exactly for the hydrogen (D) Electrocyclic reaction
atom
81. Miller indices (hkl) represent
(B) Is time dependent only (A) Unit cell dimensions
(C) Cannot predict electron energies (B) Points in a crystal
(D) Provides exact solutions for (C) Atomic coordinates
multi-electron atoms (D) Crystal faces
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82. The Michael addition is an example of 87. The hydrogen-oxygen fuel cell
(A) Free radical addition
(B) Uses KOH as electrolyte
(B) Electrophilic addition
(C) Produces CO2 as byproduct
(C) Pericyclic reaction
(D) Operates at room temperature
(D) Nucleophilic addition
88. The effect of isotopic substitution on
83. rotational constant B is
electrolyte approaches unity as the
(A) Decreases B
concentration approaches
(B) No change
(A) 1 molar
(B) Zero (C) Doubles B
(C) 0.1 molar (D) Increases B
89. The entropy change for an isothermal
reversible expansion of an ideal gas is
84. The pinacol-pinacolone rearrangement
occurs under (A) nR In(P2/P1)
(A) Neutral conditions (B) nR In(V2/V1)
(B) Basic conditions (C) Zero
(C) Photochemical conditions (D) – nR In(V2/V1)
(D) Acidic conditions
90. In which one of the following substances
85. The quantum number that determines standard enthalpy of formation is not
equal to zero ?
the shape of an orbital is
(A) Copper
(A) Magnetic quantum number (m)
(B) Hydrogen
(B) Principal quantum number (n)
(C) Phosphorus
(C) Spin quantum number (s)
(D) Diamond
(D) Azimuthal quantum number (l)
91. In an octahedral complex, the t2g orbitals
86. End group analysis is most accurate for
are
(A) Crosslinked polymers
(A) Lower in energy than eg orbitals
(B) Very high molecular weight
polymers (B) Degenerate
(C) Inorganic polymers (C) Non-bonding
(D) Low molecular weight polymers (D) Higher in energy than eg orbitals
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92. The Beckmann rearrangement converts 97. The trans
(A) Oximes to amides as
(B) Ketones to amides (A) The ratio of the ion’s concentration to
(C) Amides to amines the total ion concentration
(D) Aldehydes to amines (B) The fraction of the total current carried
by that ion
93. Liquid crystals
(A) Have random molecular arrangement (C) The ratio of the ion’s charge to the
(B) Have properties of both solids and total charge of all ions
liquids (D) The ratio of the ion’s mobility to the
(C) Are very rigid
sum of the mobilities of all ions
(D) Are always transparent
94. In light scattering experiments on 98. Liquid sulfur dioxide is considered as
polymer solutions, the intensity of
(A) Amphiprotic solvent
scattered light is proportional to
(A) Cube of molecular weight (B) Protic solvent
(B) Molecular weight (C) Non-polar solvent
(C) Square root of molecular weight (D) Aprotic solvent
(D) Square of molecular weight
95. The number of lobes in a p orbital is 99. The Gibbs-Helmholtz equation relates
(A) 3 (A) Temperature and free energy
(B) 1 (B) Pressure and volume
(C) 4 (C) Pressure and temperature
(D) 2 (D) Temperature and entropy
96. Which of the following statements about
photochemical reactions is correct ? 100. LiAlH4 reduces carboxylic acids to
(A) They require absorption of light (A) Secondary alcohols
(B) They require thermal energy only (B) Aldehydes
(C) They always produce free radicals (C) Ketones
(D) They occur only in the presence of a
(D) Primary alcohols
catalyst
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