CSIR NET CHEMISTRY (DEC-2016)
Previous Year Question Paper with Solution.
21. The HOMO (highest occupied molecular orbital) to LUMO (lowest unoccupied molecular orbital) electronic transition responsible for the observed colours of halogen molecules (gas) is
(a)
(b)
(c)
(d)
Ans. a
Sol. In halogen molecules, thetransitions are responsible for their colours as evident from the following figure
Correct option is (a)
22. In the hydrolysis to transif the leaving group is chloride, the formation of cis product is the least, when A is
(a)
(b)
(c)
(d)
Ans. a
Sol. The -donor ligands such as Cl–, Br–, I–, N-bonded NCS etc. stabilize the TBP intermediate and favour the stereochemical change. The trans-forms tendency to isomers in the order
Correct option is (a)
23. The expected number of 19F NMR spectral lines, including satellites, for is [Abundance of
(a) two
(b) twenty one
(c) three
(d) one
Ans. c
Sol.
Pentagonal Planar
as 74% Xe are NMR inactive hence a singlet of five fluorine and due to 26% nuclei a doublet of satellite.
Hence, total number of signal is 3.
Correct option is (c)
24. The expected H–H–H bond angle in is
(a) 1800
(b) 1200
(c) 600
(d) 900
Ans. c
Sol.
Each bond angle is 60º.
Correct option is (c)
25. The number of bridging ligand (s) and metal – metal bond(s) present in the complex(obeys 18 – electron rule), respectively, are
(a) 0 and 1
(b) 2 and 1
(c) 3 and 1
(d) 1 and 2
Ans. c
Sol. T.V.E. = 8 × 2 + 5 × 2 + 2 × 2 + 4 = 34 = A
B = (n × 18) – A = 36 – 34 = 2
Correct option is (c)
26. The oxidation state of gold in the following complex is
(a) 0
(b) 1
(c) 2
(d) 3
Ans. c
Sol. Oxidation state of gold in the complex is 2
Correct option is (c)
27. The rate of alkene coordination to [PtCl4]2– is highest for
(a) norbornene
(b) ethylene
(c) cyclohexene
(d) 1-butene
Ans. a
Sol. When the norbornene is strained molecule because the hybridization is sp2 when the metal attached with norbornene back -bonding takes place and due to this back -
bonding the hyberdization changes to sp2 – sp3 and hence relief to strain
Correct option is (a)
28. The nephelauxetic parameteris highest for
(a) Br–
(b) Cl–
(c) CN–
(d) F–
Ans. d
Sol. According to Nephelauxetic series
F–> H2O > NH3>en> NCS–> Cl– ~ CN–> Br–
The highest value of is for F–
Correct option is (d)
29. Thetransition in the electronic spectrum of [Cr(NH3)6]3+ occurs nearly at
(a) 650 nm
(b) 450 nm
(c) 350 nm
(d) 200 nm
Ans. a
Sol. Thetransition in the electronic spectrum of [Cr(NH3)6]3+ occurs nearly at 650 nm.
Correct option is (a)
30. In the catalytic hydration of CO2 by carbonic anhydrase, CO2 first interacts with
(a) OH group of the active site of the enzyme and then with zinc
(b) H2O of the active site of the enzyme and then with zinc
(c) zinc of the active site of the enzyme and then with OH group
(d) zinc of the active site of the enzyme and then with H2O
Ans. a
Sol. In carbonic anhydrase OH group first attack on CO2 and then CO2intract with Zn.
Correct option is (a)
31. For the reaction,
The highest value of , when X– is
(a) OCl–
(b) F–
(c) Cl–
(d)
Ans. c
Sol. Due to more acidity of HCl it will undergo more ionization. Hence, concentration of [Cl–]aq will be maximum.
Correct option is (c)
32. The correct statement for d.c. polarography is
(a) E1/2 is concentration dependent
(b) Dropping mercury electrode is a macro electrode
(c) Limiting current is equal to diffusion current
(d) A large excess of supporting electrolyte eliminates migration current
Ans. d
Sol. In d.c. polarography supporting electrolyte is taken in excess, so that all migration current is carried by supporting electrolyte. Thus electroactive species remain free from migration current
1. E1/2 does not depend on concentration of electroactive species.
2. DME is a micro electrode.
3. limiting current is sum of diffusion current and residual current
il = id + ir
Correct option is (d)
33. Saturation factor in neutron activation analysis is
(A = induced radioactivity; = neutron flux;
= effective nuclear cross section; N = no of target atoms;
= decay constant)
(a)
(b)
(c)
(d)
Ans. a
Sol. Saturation factor in neutron activation analysis.
Activity equation,
saturation factor
Saturation factor
Where, A = number of decays per second
N = number of atoms of the target isotopes
= activation cross section
= neutron flux
= decay constant
tirr = irradiation time
Correct option is (a)
34. The primary analytical method (not using a reference) is
(a) inductively coupled plasma emission spectrometry
(b) energy dispersive X-ray fluorescence spectrometry
(c) anodic stripping voltammetry
(d) isotopic dilution mass spectrometry
Ans. d
Sol. Primary analytical method is isotopic dilution mass spectrometry (not using a reference).
Correct option is (d)
35. The number of inorganic sulphur (or sulphide) atoms present in the metalloprotein active sites of rubredoxin, 2-iron ferredoxin and 4iron ferredoxin, respectively, are
(a) 0, 2 and 4
(b) 2, 4 and 3
(c) 0, 4 and 2
(d) 0, 2 and 3
Ans. a
Sol.
Correct option is (a)
36. The metal iodide with metallic lustre and high electrical conductivity is
(a) NaI
(b) CdI2
(c) LaI2
(d) BiI3
Ans. c
Sol. LaI2 exists as La3+(2I–)(e–)
The electron present is responsible for metallic cluster and high electrical conductivity.
Correct option is (c)
37. The correct order of the bond dissociation energies for the indicated C-H bond in following compounds is
(a) C > B > A
(b) A > B > C
(c) A > C > B
(d) C > A > B
Ans. d
Sol.
More s% character, stronger will be the bond.
More strong bond required more bond dissociation energy. So, the correct order of bond dissociation energy, C > B > A.
Correct option is (d)
38. The correct order of the acidity for the following compounds is
(a) B > C > A
(b) C > B > A
(c) B > A > C
(d) C > A > B
Ans. c
Sol. Cyclic are more acidic than open chain
As the ring decreases, acidity increases
(B) > (A) > (C) Least acidic
Correct option is (c)
39. The correct statement about the following compound is
(a) compound is chiral and has P configuration
(b) compound is chiral and has M configuration
(c) compound is achiral as it possesses C2-axis of symmetry
(d) compound is achiral as it possesses plane of symmetry
Ans. a
Sol.
Helical chirality, P-configurations. Since, clockwise path from front side.
Correct option is (a)
40. Methyl groups in the following compound are
(a) homotopic
(b) diasterotopic
(c) enantiotopic
(d) constitutionally heterotopic
Ans. a
Sol.
Correct option is (a)
41. Among the structures given below, the most stable conformation for the following compound is
(a)
(b)
(c)
(d)
Ans. c
Sol.
All three methyl groups on same side (above). But in option (a) : 1, 3-diaxial interaction occurs.
So, it is less stable conformation. It undergoes ring flipping to give more stable conformation as shown in option (c)
Correct option is (c).
42. Molecular orbital interactions involved in the first step of the following reaction is
(a)
(b)
(c)
(d)
Ans. a
Sol.
Correct option is (a)
43. The major product formed in the dinitration of 4-bromotoluene is
(a)
(b)
(c)
(d)
Ans. b
Sol.
Correct option is (b)
44. The correct order of the rate constants for the following series of reactions (Z = CF3/CH3/OCH3) is
(a) CF3> CH3> OCH3
(b) CF3> OCH3> CH3
(c) OCH3> CF3> CH3
(d) CH3> OCH3> CF3
Ans. a
Sol.
z = more electron withdrawing group, stabalize the carbanion, more will be rate constant.
Electron Withdrawing Effect : CF3> CH3>OMe
Correct option is (a)
45. 1H NMR spectrum of a mixture of benzene and acetonitrile shows two singlets of equal integration. The molar ratio of benzene: acetonitrile is
(a) 1 : 1
(b) 2 : 1
(c) 1 : 2
(d) 6 : 1
Ans. c
Sol. C6H6 : CH3 – CN
6H 3H
1 equivalent : 2 equivalent
6H 6H
1 : 1 (Integration ratio)
Correct option is (c)
46. The compound which shows IR frequencies at both 3314 and 2126 cm–1 is
(a) CH3(CH2)4CH2SH
(b) CH3(CH2)4CH2C=N
(c) CH3(CH2)4CH2C = C – H
(d) CH3(CH2)2C = C(CH2)2CH3
Ans. c
Sol.
Correct option is (c)
47. Number of signals present in the proton decoupled 13C NMR spectrum of the following compound is
(a) four
(b) six
(c) eight
(d) ten
Ans. a
Sol.
Molecule have plane of symmetry. So, in 13C NMR four signal.
Correct option is (a)
48. The most stable product formed in the following reaction is
(a)
(b)
(c)
(d)
Ans. a
Sol.
Correct option is (a)
49. The major product in the following reaction is
(a)
(b)
(c)
(d)
Ans. b
Sol.
Correct option is (b)
50. The major product formed in the following reaction is
(a)
(b)
(c)
(d)
Ans. d
Sol.
Simmons Smith reaction.
Simmons Smith reagent reacts on isolated double bond, to form a cyclopropane.
Correct option is (d)
51. Correct characteristics of the functional groups of adenine in DNA base pair are
(a) N(3) is a hydrogen bond acceptor and C(6)NH2 is a hydrogen bond donor
(b) N(1) is a hydrogen bond acceptor and C(6)NH2 is a hydrogen bond donor
(c) Both N(3) and C(6)NH2 are hydrogen bond acceptors
(d) Both N(1) and C(6)NH2 are hydrogen bond acceptors
Ans. b
Sol.
Correct option is (b)
52. 1H NMR spectrum of an organic compound recorded on a 500 MHz spectrometer showed a quartet with line positions at 1759, 1753, 1747, 1741 Hz. Chemical shift and coupling constant (Hz) of the quartet are
(a) 3.5 ppm, 6 Hz
(b) 3.5 ppm, 12 Hz
(c) 3.6 ppm, 6 Hz
(d) 3.6 ppm, 12 Hz
Ans. a
Sol.
Chemical shift
Coupling constant J = 1747 – 1741 = 6 Hz of difference between any two adjacent peaks (coupling constant is not change in Hertz).
Correct option is (a)
53. The weight of the configuration with two up and three down spins in a system with five spinparticles is
(a) 120
(b) 60
(c) 20
(d) 10
Ans. d
Sol.
Correct option is (d)
54. For a reaction with an activation energy of 49.8 kJ mol–1, the ratio of the rate constants at 600 K and 300 K, (k600/k300), is approximately (R = 8.3 J mol–1 K–1)
(a) ln (10)
(b) 10
(c) 10 + e
(d) e10
Ans. d
Sol.
Correct option is (d)
55. Covariance is defined by the relationGiven the arbitrary constants A, B and
will be zero only when
(a)
(b)
(c)
(d)
Ans. c
Sol. Covariance shows the tendency in the linear relationship between the variables.
Correct option is (c)
56. Each void in a two dimensional hexagonal close-packed layer of circles is surrounded by
(a) six circles
(b) three circles
(c) four circles
(d) twelve circles
Ans. b
Sol. From figure it is clear that each void is surrounded by three circles.
Correct option is (b)
57. The ionic mobilities ofrespectively. The transport numbers of
are, respectively
(a) 0.545 and 0.455
(b) 0.455 and 0.545
(c) 0.90 and 0.910
(d) 0.910 and 0.090
Ans. a
Sol.
Correct option is (a)
58. The ionic strength of a solution containing 0.008 M AlCl3 and 0.005 M KCl is
(a) 0.134 M
(b) 0.053 M
(c) 0.106 M
(d) 0.086 M
Ans. b
Sol.
Correct option is (b)
59. The correct normalized wavefunction for one of the sp2 hybrid orbitals is
(a)
(b)
(c)
(d)
Ans. c
Sol. For normalised wave function,
Correct option is (c)
60. The correct statement in the context of NMR spectroscopy is
(a) static magnetic field is used to induce transition between the spin states
(b) magnetization vector is perpendicular to the applied static magnetic field
(c) the static magnetic field is used to create population difference between the spin states
(d) static magnetic field induces spin-spin coupling
Ans. c
Sol. In NMR spectroscopy the static magnetic field is used to create population difference between the spin states
Correct option is (c)
61. The parameter which always decreases during a spontaneous process at constant S and V, is
(a) U
(b) H
(c) Cp
(d) q
Ans. a
Sol. dU = +TdS – PdV
If S & V are constant, then equation (1) becomes
(dU)S, V < 0
Criteria of spontaniety.
Correct option is (a)
62. Triple point pressure of substances A, B, C and D are 0.2, 0.5, 0.8 and 1.2 bar, respectively. The substance which sublimes under standard conditions on increasing temperature is
(a) A
(b) B
(c) C
(d) D
Ans. d
Sol. Standard condition means 1 bar pressure
For A
So at 1 bar transition will be solidliquid. So number sublimation
For B
Same explanation as above
Correct option is (d)
63. According to the transition state theory, the plot with slope equal to is
(a) ln k vs. T
(b)
(c)
(d)
Ans. c
Sol.
Correct option is (c)
64. The transition that belongs to the Lyman series in the hydrogen-atom spectrum is
(a)
(b)
(c)
(d)
Ans. b
Sol. For allowed transition,and for Lyman Series Transition is from higher level to n = 1
Correct option is (b)
65. The molecule that possesses S4 symmetry element is
(a) ethylene
(b) allene
(c) benzene
(d) 1, 3 – butadiene
Ans. b
Sol.
Correct option is (b)
66. Vibrations of diatomic molecules are usually modelled by a harmonic potential. If the? potential is given by x2, the correct statement is
(a) force is 2x and force constant is 2
(b) force is –2x and force constant is 2
(c) force is 2x and force constant is –1
(d) force is –2x and force constant is –1
Ans. b
Sol. Given: V = x2
Correct option is (b)
67. When 1 × 10–5 of a fatty acid (M = 602.3 g/mol) was placed on water as a surface film, a monomolecular layer of area 100 cm2 was formed on compression. The cross-sectional area (in Å2) of the acid molecule is
(a) 50
(b) 100
(c) 150
(d) 200
Ans. b
Sol. Total surface area = Number of molecules × Area covered by 1 mole (A1)
Correct answer is (b)
68. Mark – Gouwink equation is used for the determination of
(a) number-average molar mass
(b) weight-average molar mass
(c) viscosity-average molar mass
(d) z-average molar mass
Ans. c
Sol.
Correct answer is (c)
69. Many properties of nanoparticles are significantly different than the corresponding bulk material due to
(a) smaller band gap of nanoparticles compared to bulk
(b) higher heterogeneity of the nanoparticle solutions
(c) larger ratio of surface area to volume of the nanoparticles compared to the bulk
(d) smaller ratio of surface?area to volume of the nanoparticles compared to the bulk
Ans. c
Sol. Many properties of nano-particles are significantly different than the corresponding bulk material because large ratio of surface area to volume of nano-particles in compare to the bulk.
Correct option is (c)
70. The correct match for the following is
(a) (i) – (A); (ii) – (C); (iii) – (E)
(b) (i) – (E); (ii) – (B); (iii) – (A)
(c) (i) – (D); (ii) – (C); (iii) – (A)
(d) (i) – (E); (ii) – (B); (iii) – (D)
Ans. b
Sol. Camphor Terpene
Insulin Hormone
Keratin Structural Protein
Correct option is (b)
71. Consider the following statements for KC8:
(A) It is paramagnetic,
(B) It has eclipsed layer structure,
(C) Its electrical conductivity is greater than that of graphite. The correct answer is
(a) A and B
(b) A and C
(c) B and C
(d) A, B and C
Ans. d
Sol. 8C(graphite) + K+(am) + e–(am)
[K (am)]+ [C8]– (s)
to the presence of unpaired electrons in band of graphite it is paramagnetic and its electrical conductance increases. It has eclipsed layer structure
Correct option is (d)
72. Among the following, choose the correct products that are formed in the reaction of S2Cl2 with ammonia in CCl4:
NH4Cl (A), S4N4 (B), Sg (C), and S3N3Cl3 (D).
(a) A, B and C
(b) A, B and D
(c) B, C, and D
(d) A, C and D
Ans. a
Sol.
Correct option is (a)
73. For [Ce(NO3)4(OPPh3)2], from the following
A. Its aqueous solution is yellow-orange in colour
B. Coordination number of Ce is ten
C. It shows metal to ligand charge transfer
D. It is diamagnetic in nature
the correct answer is
(a) A and B
(b) A and C
(c) A, B and D
(d) B, C and D
Ans. c
Sol.
ND unpaired electrons.
It is diamagnetic and its colour is due to LMCT. Its C.N. = 10
Correct option is (c)
74. Consider the following statements, I and II:
I: [Rh(CO)2I2]– catalytically converts CH3I and CO to CH3COI
II: [Rh(CO)2I2]– is diamagnetic in nature
The correct from the following is
(a) I and II are correct and II is an explanation of I
(b) I and II are correct and II is not an explanation of I
(c) I is correct and II is incorrect
(d) I and II are incorrect
Ans. b
Sol.
I and II are correct but II is not correct explanation of I.
Correct explanation : Monsanto process occurs via oxidative reaction, migratory insertion and reductive elimination reaction for that the starting compound must be square planar.
Correct option is (b)
75. In a direct isotopic dilution method for determination of phosphate, 2 mg of 32PO43– (specific activity 3100 disintegration s–1 mg–1) was added to 1g of a sample solution. The 30 mg of phosphate isolated from it has an overall activity of 3000 disintegration s–1. The % mass of PO43– in the sample is
(a) 30
(b) 6
(c) 9
(d) 15
Ans. b
Sol. In 30 mg sample the overall activity is 3000 s–1. So, mass of 12PO4–2 is
Correct answer is (b)
76. Consider the following statements for [FeO4]4–.
A. It is paramagnetic
B. It has Td symmetry
C. Adopts distorted square planar geometry
D. Shows approximately D2d symmetry
The correct answer is
(a) A, B and C
(b) A, C and D
(c) A and D
(d) A and B
Ans. c
Sol. Jahn Teller distorted away from the ideal tetrahedral towards a flatterred structure
It is paramagnetic due to unpaired electron D2d symmetry.
Correct option is (c)
77. The geometry of [ReH9]2– is
(a) monocapped square antiprism
(b) monocapped cube
(c) tricapped trigonal prism
(d) heptagonal bipyramid
Ans. c
Sol. Tricapped trigonal prismatic
Atoms 1 to 6 are the prism atoms, 7 to 9 are H-atom are equatorial hydrogen.
Correct option is (c)
78. The reaction between PI3, PSCl3 and zinc powder gives P3I5 as one of the products. The solution state 31P NMR spectrum of P3I5 shows a doublet
and a triplet
The correct structure of P3I5 is
(a)
(b)
(c)
(d)
Ans. c
Sol. Correct structure is
. One c2 axis and one plane of symmetry exist in this molecules.
So, two types of phosphorous atoms
Correct option is (c)
79. Some molecules and their properties in liquid ammonia are given in columns A and B respectively. Match column A with column B
The correct match is
(a) (A) – (i); (B) – (ii); (C) – (iii); (D) – (iv)
(b) (A) – (ii); (B) – (iii); (C) – (iv); (D) – (i)
(c) (A) – (iii); (B) – (iv); (C) – (i); (D) – (ii)
(d) (A) – (iv); (B) – (iii); (C) – (ii); (D) – (i)
Ans. d
Sol. solvolysis and disproportionation of Cl2 in NH3
undergoes disproportionation in liquid NH3
CH3COOH acts as strong acid in NH3
Molecules that do not behave as acid in water, may behave as weak acids in NH3.
Correct option is (d)
80. The spectroscopic ground state term symbols for the octahedral aqua complexes of Mn(II), Cr(III) and Cu(II), respectively, are
(a) 2H, 4F and 2D
(b) 6S, 4F and 2D
(c) 2H, 2H and 2D
(d) 6S, 4F and 2P
Ans. b
Sol. is a weak ligand, No pairing occurs.
Correct answer is (b)
81. From the following transformations,
A. Epoxidation of alkene
B. Diol dehydrase reaction
C. Conversion of ribonucleotide – to – deoxyribonucleotide
D. 1, 2 – carbon shift in organic substrates
those promoted by coenzyme B12 are
(a) A and B
(b) B, C and D
(c) A, B and D
(d) A, B and C
Ans. b
Sol. Co-enzyme B12 catalyses dehydration, 1, 2-carbon shift reaction.
Hence, Correct option is (b)
82. Match the items in column A with the appropriate items in column B
The correct answer is:
(a) (A) – (ii); (B) – (iii); (C) – (v); (D) – (iv)
(b) (A) – (ii); (B) – (iii); (C) – (iv); (D) – (i)
(c) (A) – (ii); (B) – (iii); (C) – (v); (D) – (vi)
(d) (A) – (iii); (B) – (v); (C) – (vi); (D) – (ii)
Ans. c
Sol. Metallothionines Cystein rich protein
Plastocyanin Electron transfer
Ferritin Iron storage
Chemotherapy Carboplatin
Correct option is (c)
83. For OH– catalysed SN1 conjugate base mechanism of [Co(NH3)5Cl]2+, the species obtained in the first step of the reaction is/are T
(a) [Co(NH3)5(OH)]2+ + Cl–
(b) [Co(NH3)4(NH2)Cl]+ + H2O
(c) [Co(NH3)4(NH2)]2+ + Cl–
(d) [Co(NH3)5Cl(OH)]+ only
Ans. b
Sol.
Correct answer is (b)
84. Match the species in column X with their properties in column Y
Column X Column Y
(a) Heme A (i) oxo-bridged Mn4 cluster
(b) water spliting enzyme (ii) tetragonal elongation
(c) [Mn(H2O)6]2+ (iii) predominantly electronic transitions
(d) [Cr(H2O)6]2+ (iv) d d spinforbidden transitions
(v) tetragonal compression
Ans. b
Sol. Heme A Iron porphyrin
Colour due to
water splitting enzyme contains transition 0 × 0 bridged Mn4 cluster
Correct option is (b)
85. According to isolobal analogy, the right set of fragments that might replace Co(CO)3 in [Co4(CO)12] is
(a) CH, BH and Mn(CO)5
(b) P, CH and
(c) Fe(CO)4, CH2 and SiCH3
(d) BH, SiCH3 and P
Ans. b
Sol. Co(CO)3
9 + 6 = 15 (for 18 electron require 3 electron)
Correct answer is (b)
86. According to Wade's rules, the correct structural types of and
are
(a) closo and nido
(b) nido and arachno
(c) closo and aracarachno
(d) nido and nido
Ans. b
Sol.
Correct answer is (b)
87. The correct geometry of
(a) octahedron
(b) pentagonal pyramid
(c) trigonal prism
(d) monocapped square pyramid
Ans. c
Sol.
TVE = 9 × 6 + 4 + 15 × 2 + 2 = 54 + 4 + 2 + 30 = 90
Hence, it has trigonal prism geometry.
Correct option is (c)
88. The final product(s) of the reaction of arachno borane, B4H10 with NMe3 is/are
(a)
(b)
(c)
(d) 4
Ans. a
Sol.
Correct answer is (a)
89. Product A in the following reaction is
(a)
(b)
(c)
(d)
Ans. c
Sol.
Correct answer is (c)
90. Treatment of Fe(CO)5 with 1, 3 – butadiene gives B that shows two signals in its 1H NMR spectrum. B on treatment with HCl yields C which shows four signals in its 1H NMR spectrum. The compound C is
(a)
(b)
(c)
(d)
Ans. b
Sol.
Compound (C) has show four 1H NMR signal
Correct option is (b)
91. In the following redox reaction with an equilibrium constant K = 2.0 × 108,
the self exchange rates for oxidant and reductant are 5.0 M–1s–1 and 4.0 × 103 M–1s–1, respectively. The approximate rate constant (M–1s–1) for the reaction is
(a) 3.16 × 106
(b) 2.0 × 106
(c) 6.32 × 106
(d) 3.16 × 104
Ans. b
Sol. k12 = (k11K k22f)1/2 = (5 × 4 × 103 × 2 × 108 × 1.0)1/2 = 20 × 105 = 2.0 × 106
Correct option is (b)
92. The correct statement for a Fischer carbene complex is
(a) the carbene carbon is electrophilic in nature
(b) metal exists in high oxidation state
(c) metal fragment and carbene are in the triplet states
(d) CO ligands destabilize the complex
Ans. a
Sol. Fischer carbene carbon is electrophilic in nature due to strong -acceptor ligands
Correct option is (a)
93. The acidic solution containing trimethylamine (A), dimethylamine (B) and methyl amine (C) (pKa of cations 9.8, 10.8 and 10.6, respectively) was loaded on a cation exchange column. The order of their elution with a gradient of increasing pH > 7 is
(a) A < C < B
(b) B < C < A
(c) B < A < C
(d) C < B < A
Ans. a
Sol. (A) trimethylamine pKa 9.8
(B) dimethylamine pKa 10.8
(C) methyl amine pKa 10.6
pH > 7 is a basic pH and amine with lower pKa value will give the proton easily, and will elute at last.
Correct option is (a)
94. For complex A, deuterationof NH protons does not alter the EPR spectrum. The number of hyperfine lines expected in the EPR spectrum of A is
(a) 20
(b) 12
(c) 60
(d) 36
Ans. a
Sol. Number of hyperfine line (due to Cu and nitrogen)
Correct option is (a)
95. The numbers of triangular faces in square antiprism, icosahedron and tricapped trigonal prism (capped on square faces), respectively, are
(a) 8, 20 and 14
(b) 8, 20 and 12
(c) 10, 12 and 14
(d) 10, 12 and 12
Ans. a
Sol. Number of triangular anti-prism are 8, in icosahedron it is 20 and in tricapped trigonal prism capped on square faces) it is 14
Correct answer is (a)
96. Number of lines in the 19F NMR spectrum of F2C(Br) – C(Br)Cl2 at – 1200C assumping it a mixture of static conformations given below, are
(a) One
(b) Two
(c) Four
(d) five
Ans. d
Sol.
Both fluorine in same environment.
Correct answer is (d)
97. The correct statement for the reactants A, B to give products C, D is
(a) A gives C and B give D
(b) A gives D and B gives C
(c) A and B give identical amounts of C and D
(d) A and B give D
Ans. c
Sol.
Correct answer is (c)
98. The major product formed in the following reaction is
(a)
(b)
(c)
(d)
Ans. c
Sol.
Correct answer is (c)
99. The major product formed in the following reaction is
(a)
(b)
(c)
(d)
Ans. b
Sol.
Correct answer is (b)
100. The compound that exhibits following spectral data is
(a)
(b)
(c)
(d)
Ans. c
Sol.
Spectral edata confirms the Para-pattern, so option (a) and (b) ruled out. Options (c) and (d) may be correct but in option (d), the methyl are non-equivalent due to resonating structure, exhibit different signal. But in option (c), two methyl group are chemical equivalent and exhibits a singlet of 6-Hs.
Correct option is (c)
101. The major product in the following reaction is
(a)
(b)
(c)
(d)
Ans. d
Sol.
102. The major product formed in the following reaction is
NIS : N – iodosuccinimide
(a)
(b)
(c)
(d)
Ans. b
Sol.
Correct answer is(b)
103. The major product formed in the following reaction is
(a)
(b)
(c)
(d)
Ans. b
Sol.
Correct option is (b)
104. The major product formed in the following reaction is
(a)
(b)
(c)
(d)
Ans. a
Sol.
Correct answer is (a)
105. Correct sequence of reagents for the following conversion is
(a) (i) K2CO3, (ii) HC
CCOCH3, (iii) Br2, (iv) NaBH4
(b) (i) NaBH4, (ii) HC CCOCH3, (iii) Br2, (iv) K2CO3
(c) (i) HC CCOCH3, (ii) K2CO3, (iii) Br2, (iv) NaBH4
(d) (i) Br2, (ii) HC CCOCH3, (iii) K2CO3, (iv) NaBH4
Ans. a
Sol.
Correct option is (a)
106. The major product in the following reaction is
(a)
(b)
(c)
(d)
Ans. b
Sol. This is Julia Olefinations reactions, under the given set of reaction E-alkene is formed. The detail mechanism is shown below.
Correct answer is (b)
107. For the four reactions given below, the rates of the reactions will vary as
(a) 1 > 2 and 3 > 4
(b) 2 > 1 and 3 > 4
(c) 2 > 1 and 4 > 3
(d) 1 > 2 and 4 > 3
Ans. d
Sol.
–R effect of this group, increase stability of intermediate.
In that case electron withdrawing group increase the rate of reaction.
EWG containing carbocation intermediate decrease the stability.
Correct answer is (d)
108. The major product formed in the following reaction is
(a)
(b)
(c)
(d)
Ans. a
Sol.
Correct answer is (a)
109. The correct sequence of pericyclic reactions involved in the following transformation is
(a) (i) ene reaction, (ii) [2, 3]-sigmatropic shift, (iii) [3, 3]-sigmatropic shift
(b) (i) ene reaction, (ii) [3, 3]-sigmatropic shift, (iii) [1, 3]-sigmatropic shift
(c) (i) [2, 3]-sigmatropic shift, (ii) ene reaction, (iii) [1, 3]-sigmatropic shift
(d) (i) [1, 3]-sigmatropic shift, (ii) [2, 3] sigmatropic shift, (iii) [3, 3]-sigmatropic shift
Ans. a
Sol.
Correct answer is (a)
110. The intermediate that leads to the product in the following transformation is
(a)
(b)
(c)
(d)
Ans. b
Sol.
Correct answer is (b)
111. Product(s) of the following reaction is (are) [* – indicates isotopically labelled carbon]
(a)
(b)
(c)
(d)
Ans. c
Sol.
Correct answer is (c)
112. The major product formed in the following reaction is
(a)
(b)
(c)
(d)
Ans. a
Sol. Coupling reaction
Correct option is (a)
113. The major product formed in the following reaction is
(a)
(b)
(c)
(d)
Ans. d
Sol.
Correct option is (d)
114. The major product formed in the following reaction is
(a)
(b)
(c)
(d)
Ans. d
Sol.
Correct option is (d)
115. Correct match for the products of the reactions in Column–A with the properties in Column – B is
(a) (i) – P, (ii) – S, (iii) – R, (iv) – Q
(b) (i) – P, (ii) – R, (iii) – Q, (iv) – S
(c) (i) – Q, (ii) – R, (iii) – S, (iv) – P
(d) (i) – S, (ii) – Q, (iii) – R, (iv) – P
Ans. a
Sol.
Correct option is (a)
116. The correct starting compound A in the following reaction is
(a)
(b)
(c)
(d)
Ans. b
Sol.
Correct answer is (b)
117. The major product formed in the following reaction is
(a)
(b)
(c)
(d)
Ans. b
Sol.
Correct option is (b)
118. The major product formed in the following reaction is
.
(a)
(b)
(c)
(d)
Ans. a
Sol. Barton reaction:
Correct option is (a)
119. The major product formed in the following reaction is
(a)
(b)
(c)
(d)
Ans. b
Sol.
Correct answer is (b)
120. The major product formed in the following reaction is
(a)
(b)
(c)
(d)
Ans. d
Sol. DDQ used for deprotection of benzylether through one electron oxident process. As the number of OMe increases on the aryl ring, reactivity towards deprotection increases. So,
Correct answer is (d)
121. A constant of motion of hydrogen atom in the presence of spin-orbit coupling is
(a)
(b) s
(c)
(d)
Ans. c
Sol.
For constant of motion C, we must have
Correct option is (c)
122. The orbital degeneracy of the level of a oneelectron atomic system with Z = 5 and energy is
(a) 1
(b) 5
(c) 25
(d) 36
Ans. c
Sol.
Therefore, orbtial degeneracy = n2 = 25.
Correct option is (c)
123. If we write a normalized wavefunction is also normalized when
(a)
is hermitian
(b) is anti-hermitian
(c) is unitary
(d) is any linear operator
Ans. c
Sol.
124. The ground state of a certain system with energy is subjected to a perturbation V, yielding a first-order correction
If E0 is the true ground – state energy of the perturbed system, the inequality that always holds is
(a)
(b)
(c)
(d)
Ans. *
Sol. According to Perturbation theory, "The energy of perturbed system is equal or greater than the standard system."
Correct option is (*)
125. The spatial part of an excited state b of hydrogen molecule is proportional to
Using LCAO – MO expansion of
in terms of ls – atomic orbitals, one can infer that this wavefunction has
(a) only ionic parts
(b) only covalent parts
(c) both ionic and covalent parts
(d) neither ionic nor covalent parts
Ans. b
Sol.
Correct option is (b)
126. The highest molecular orbitals for an excited electronic configuration of the oxygen molecule are A possible molecular term symbol for oxygen with this electronic configuration is
(a)
(b)
(c)
(d)
Ans. a
Sol. The arrangements for configurations are
Thus one of possible molecular term symbol is
Correct answer is(a)
127. For H2O molecule, the electronic transition from the ground state to an excited state of B1 symmetry is
(a) not allowed
(b) allowed with polarisation
(c) allowed with polarisation
(d) allowed with polarisation
Ans. b
Sol.
128. The pair of symmetry point groups that are associated with only polar molecules is
(a)
(b)
(c)
(d)
Ans. d
Sol. The polar point group are
Correct option is (d)
129. The rotational constant and the fundamental vibrational frequency of HBr are, respectively, 10 cm–1 and 2000 cm–1. The corresponding values for DBR approximately are
(a) 20 cm–1 and 2000 cm–1
(b) 10 cm–1 and 1410 cm–1
(c) 5 cm–1 and 2000 cm–1
(d) 5 cm–1 and 1410 cm–1
Ans. d
Sol.
Correct answer is (d)
130. Among the following, both microwave and rotational Raman active molecule is
(a) CH4
(b) N2O
(c) C2H4
(d) CO2
Ans. b
Sol. N2O is microwave and rotational Raman active molecule.
Correct option is (b)
131. In a 200 MHz NMR spectrometer, a molecule shows two doublets separated by 2 ppm. The observed coupling constant is 10 Hz. The separation between these two signals and the coupling constant in a 600 MHz spectrometer will be, respectively
(a) 600 Hz and 30 Hz
(b) 1200 Hz and 30 Hz
(c) 600 Hz and 10 Hz
(d) 1200 Hz and 10 Hz
Ans. d
Sol.
So, at 600 MHz, 2ppm = 1200 Hz. Hence, correct option is (d)
132. The equation of state for one mole of gas is given by P(V – b) = RT, where b and R and constants. The value of
(a) V – b
(b) b
(c) 0
(d)
Ans. b
Sol. dH = TdS + UdP
This is T.E.S. II
Now for given gas
Constant P on differentiating with respect to T
Correct option is (b)
133. The volume change in a phase transition is zero. From this, we may infer that the phase boundary is represented by
(a)
(b)
(c)
(d)
Ans. a
Sol. According to Clapyeron equation
Correct option is (a)
134. The partial derivative is equal to
(a)
(b)
(c)
(d)
Ans. a
Sol.
Now, according to reciprocal theorem of partial derivatives
Putting these values in equation (1), we get
Correct option is (a)
135. If the energies of a bare proton aligned alonge and against an external static magnetic field (Bz) are
respectively, then the ratio of probabilities of finding the proton along and against the magnetic field is
(a)
(b)
(c)
(d)
Ans. d
Sol.
Rate of probability of finding the proton along end against magnetic field
Correct option is (d)
136. Partition function of a one – dimensional oscillator having equispaced energy levels with energy spacing equal to kBT and zero ground state energy is
(a) e
(b)
(c)
(d)
Ans. c
Sol. Since, zero point energy = 0
Correct option is (c)
137. A reaction goes through the following elementary steps
Assuming that steady state approximation can be applied to C, on doubling the concentration of A, the rate of production of D will increase by (assuming k2[A]<<k–1[C])
(a) 2 times
(b) 4 times
(c) 8 times
(d)
Ans. d
Sol. Rate of production of D
Applying SSA on 'C',
Correct option is (d)
138. The rate of an acid-catalyzed reaction in aqueous solution follows the rate equation
If k16 and k4 are rate constants for the reactions at ionic strength of 16 mo1L–1 and 4 molL–1, respectively,
in terms of Debye – Hückel constant (B = 0.51), is
(a) 4B
(b) 8B
(c) 10B
(d) 12B
Ans. d
Sol.
Correct answer is (d)
139. For two reactions,
According to the collision theory, the ratio of squares of pre – exponential factors of reactions 2 (A2) and 1(A1) at the same temperature,
(a) 4/5
(b) 5/5
(c) 5/3
(d) 3/5
Ans. a
Sol. Pre-exponential factor in collision Theory,
Correct option is (a)
140. If the specific conductances of a sparingly (1 : 1) salt (MW = 200 g mol–1) in its saturated aqueous solution at 250C and that of water are 1.5 × 10–3 ohm–1 and 1.5 × 10–5 ohm–1 dm–1, respectively, and the ionic conductances for its cation and anion at infinite dilution are 0.485 and 1.0 ohm–1 dm–1, respectively, the solubility (in g L–1) of the salt in water at 250C is
(a) 1 × 10–6
(b) 1 × 10–3
(c) 2 × 10–1
(d) 2 × 10–4
Ans. c
Sol.
Correct option is (c)
141.
The formation constant of the complex is approximately
(a) 1 × 105
(b) 1 × 107
(c) 1 × 109
(d) 1 × 1012
Ans. c
Sol.
on reversing 2nd reaction and adding it to reaction 1
Equilibrium constant of above cell reaction is formation constant
But values in equation given are of oxidation potential
Correct option is (c)
142. The molar conductivity ( Ʌ ) vs. concentration (c) plot of sodium dodecylsulfate in water is expected to look like
(a)
(b)
(c)
(d)
Ans. d
Sol. The molar conductance of anionic surfactant of the type Na+R– (sodium dodecylsulfate in water) in water is plotted against the square root of the normality of the solution. The curve obtained, instead of being the smoothly decreasing curve characteristic of ionic electrolytes of this type, has a sharp break in it, at low concentrations. This sharp break in the curve accompanied by reduction in the conductance of the solution, indicating a sharp increase in the mass per unit charge of the material in solution, is interpreted as evidence for the formation of micelles at that point from the unassociated molecules of surfactant with part of the charge of the micelle neutralized by associated counter ions. The concentration at which this phenomenon occurs is called the critical micelle concentration (CMC)
The effect of concentration of electrolyte is given by
For homologous ionic surfactant
Correct option is (d)
143. The values obtained from X-ray powder diffraction pattern of a solid are 2x, 4x 6x, 8x where x is equal to 0.06. The wavelength of X – ray used to obtain this pattern is 1.54Å. The until cell and the until cell length, respectively are
(a) BCC, 3.146 Å
(b) FCC, 3.146 Å
(c) SCC, 6.281 Å
(d) BCC, 1.544 Å
Ans. a
Sol.
Correct option is (a)
144. Distribution of molar masses in a typical polymer sample is shown below.
The A, B and C represent
(a)
(b)
(c)
(d)
Ans. b
Sol.
Correct option is (b)
145. Two bound stationary states, 1 and 2, of a one – electron atom, with E2 > E1 (E is the total energy) obey the following statement about their kinetic energy (T) and potential energy (V)
(a) T2 > T1 ; V2 > V1
(b) T2 > T1 ; V2 < V1
(c) T2 < T1 ; V2 > V1
(d) T2 = T1 ; V2 > V1
Ans. c
Sol.
Correct option is (c)