(a) NaBH₄

(b) LiAlH₄

(c) H₃B·THF

(d) Zn(Hg)/HCl

Ans. d

Sol.

2. The major product formed in the following reaction

(a)

(b)

(c)

(d)

Ans. (b)

Sol.

3. The major product formed in the following reaction

(a)

(b)

(c)

(d)

Ans. (a)

Sol.

4. The major product formed in the following reaction

K+ O₂ is

(a) K₂O

(b) K₂O₂

(c) KO₂

(d) K₂O₃

Ans. (c)

Sol. K + O₂ KO₂

5. Which one of the following options is best suited for effecting the transformation?

(a) MnO₂

(b) DMSO, (COCl)₂, Et₃N

(c) Al(Oi-Pr)₃

(d) Ag₂O/NH₄OH

Ans. (d)

Sol.

Al(O – iso – Pr)₃ and DMSO, (CoCl)₂, NH₃ will also react with – OH

MnO₂ is generally used to oxidiseallylic – OH.

6. The structure of [XeF₈]^2– is

(a) cubic

(b) hexagonalbipyramid

(c) squareantiprism

(d) octagonal

Ans. (c)

Sol.

7. Among the following, the compound that forms the strongest hydrogen bond is

(a) HF

(b) HCl

(c) HBr

(d) HI

Ans. (a)

Sol. Among the following, the compound that forms the strongest hydrogen bond is for strongtest 'H' bonding more +ive charge 'H'

Correct option is (a)

8. Among the following, the biomolecule with a direct metal-carbon bond is

(a) coenzyme B₁₂

(b) nitrogenase

(c) chlorophyll

(d) hemoglobin

Ans. (a)

Sol. The reaction of adenosine phosphate (ATP) with Vit-B_12S field direct cobalt – carbon bond between adenosyl and cobalt the resulting molecule is known as B₁₂ coenzyme.

9. For the reaction

H₂PO₂^– (aq) + OH^– (aq) HPO₃^2– (aq) + H₂(g)

the rate expression is k[H₂PO₂^–][OH^–]². If the concentration of H₂PO₂^– is doubled, the rate is

(a) tripled

(b) halved

(c) doubled

(d) unchanged

Ans. (c)

Sol. Rate₁ = K [H₂PO₂^–]¹ [OH^–]²

When conc. of [H₂PO₂]^– is doubled, new rate

Rate₂ = K [2H₂PO₂^–]¹ [OH]²

= 2 K[H₂PO₂^–] [OH^–]²

= 2 × Rate₁

Rate becomes doubled

10. The nature of interaction involved at the gas-solid interface in physisorption is

(a) ionic

(b) van der Waals

(c) hydrogen bonding

(d) covalent

Ans. (b)

Sol. Asinphysiosorption weak vanderwaal force of interaction is responsible for adsorption.

11. The major product formed in the following reaction

(a)

(b)

(c)

(d)

Ans. (c)

Sol.

12. An organic compound having molecular formula C₉H₁₀O₂ exhibits the following spectral characteristics:

¹H NMR: 9.72 (t, 1H), 7.1 (d, 2H), 6.7 (d, 2H), 3.8 (s, 3H), 3.6 (d, 2H)

IR: 1720 cm^–1

The most probable structure of the compound is

(a)

(b)

(c)

(d)

Ans. (c)

Sol. NMR structure determination

13. The major product formed in the reaction of (2S,3R)-2-chloro-3-phenylbutane with NaOEt in EtOH is

(a) (E)-2-phenyl-but-2-ene

(b) (Z)-2-phenyl-but-2-ene

(c) 3-phenyl-but-1-ene

(d) (2R,3R)-2-ethoxy-3-phenylbutane

Ans. (b)

Sol.

14. The major product formed in the following reaction

(a)

(b)

(c)

(d)

Ans. (c)

Sol.

15. The reactivity of the enol derivatives

towards benzaldehyde follows the order

(a) I > II > III

(b) III > II > I

(c) II > I > III

(d) I > III > II

Ans. (d)

Sol. More the ionic character of O – M bond more is the –ve charge on oxygen and more isthe reactivity.

Trend of ionic character of O – M bond:

O – Li > O – ZnBr> O – SiMe₃

Same is the trend for reactivity of enol. derivatives.

16. All possible lattice types are observed in the

(a) cubic crystal system

(b) monoclinic crystal system

(c) tetragonal crystal system

(d) orthorhombic crystal system

Ans. (d)

Sol. In orthorhombic crystal system, premittive, body centered, face centered & end centered bravious lattices are present.

17. The structure types of B₁₀H₁₀^2– and B₁₀H₁₄ , respectively, are

(a) closo and nido

(b) nido and arachno

(c) nido and closo

(d) closo and arachno

Ans. (a)

Sol.

18. The ground state and the maximum number of spin-allowed electronic transitions possible in a Co²⁺ tetrahedral complex, respectively, are

(a) ⁴A₂ and 3

(b) ⁴T₁ and 2

(c) ⁴A₂ and 2

(d) ⁴T₁ and 3

Ans. (a)

Sol. Co²⁺(td) d⁷ 2e^– system

Ground state ⁴A₂

Number of transition observed = 3

19. The correct statement about the geometries of BH₂⁺ and NH₂⁺ based on valence shell electron pair repulsion (VSEPR) theory is

(a) both BH₂⁺ and NH₂⁺ are trigonal planar

(b) BH₂⁺ is linear and NH₂⁺ is trigonal planar

(c) BH₂⁺ is trigonal planar and NH₂⁺ is linear

(d) both BH₂⁺ and NH₂⁺ are linear

Ans. (b)

Sol. Geometry of NH₂⁺ and BH₂⁺

20. The order of increasing CO stretching frequencies in [Co(CO)₄]^–, [Cu(CO)₄]⁺, [Fe(CO)₄]^2– and [Ni(CO)₄] is

(a) [Cu(CO)₄]⁺< [Ni(CO)₄] < [Co(CO)₄]^–< [Fe(CO)₄]^2–

(b) [Fe(CO)₄]^2–< [Co(CO)₄]^–< [Ni(CO)₄] < [Cu(CO)₄]⁺

(c) [Co(CO)₄]^–< [Fe(CO)₄]^2–< [Cu(CO)₄]⁺< [Ni(CO)₄]

(d) [Ni(CO)₄] < [Cu(CO)₄]⁺< [Co(CO)₄]^–< [Fe(CO)₄]^2–

Ans. (**)

Sol.

21. The reaction of 2,4-dinitrofluorobenzene with hydrazine produces a yellow orange solid X used for the identification of an organic functional group G. X and G, respectively, are

(a)

(b)

(c)

(d)

Ans. (b)

Sol.

22. The stability of adducts H₃B·PF₃, H₃B·NMe₃, H₃B·CO, H₃B·OMe₂ follows the order

(a) H₃B·OMe₂< H₃B·CO < H₃B·PF₃< H₃B·NMe₃

(b) H₃B·PF₃< H₃B·CO < H₃B·NMe₃< H₃B·OMe₂

(c) H₃B·CO < H₃B·PF₃< H₃B·NMe₃ . H₃B·OMe₂

(d) H₃B·PF₃< H₃B·CO < H₃B·OMe₂ . H₃B·NMe₃

Ans. (d)

Sol. When good lewis acid binds with good lewisbase then stable adduct formation will occurs.

(d) H₃B·PF₃< H₃B·CO < H₃B·OMe₂ . H₃B·NMe₃

Correct option is (d)

in option (c) < H₃B · NMe₃< H₃B · OMe₂

23. The spacing between successive rotational energy levels of a diatomic molecule XY and its heavier isotopic analogue X'Y' varies with the rotational quantum number, J, as

(a)

(b)

(c)

(d)

Ans. (d)

Sol. E_J+1 – E_J = 2B (J+1)

slope = 2B, intercept = 2B

24. The ratio of the 2p 1s transition energy in He⁺ to that in the H atom is closest to

(a) 1(b) 2

(c) 4

(d) 8

Ans. (c)

Sol. H Z = 1

E₁ – E₂ = – 13.6 × 4 – (–13.6)

= – 13.6 × 4 + 13.6

25. The phase diagram of water is best represented by

(a)

(b)

(c)

(d)

Ans. (d)

Sol. The phase diagram of water is best represented by a diagram that shows the relationship between temperature, pressure and the different phaes of water: Solid (ice), liquid (water) and gas (vapour)

For water,

Hence, required phae diagram of water is:

26. Capillary W contains water and capillary M contains mercury. The contact angles between the capillary wall and the edge of the meniscus at the air-liquid interface in W and M are W and M , respectively.

The contact angles satisfy the conditions

(a)

(b)

(c)

(d)

Ans. (d)

Sol. Water < 90º

27. The Maxwell-Boltzmann distribution of one-dimensional velocities at temperature T is

[Given: A is a normalization constant such that and k_B is the Boltzmann constant]

(a)

(b)

(c)

(d)

Ans. (a)

Sol. Number of particle in velocity range

Correct option is (a)

28. The potential for a particle in a one-dimensional box is given as:

V(x) = 0 for 0 < x < L, and V(x) = elsewhere.

The locations of the internal nodes of the eigenfunctions (x) , n > 2, are

[Given: m is an integer such that 0 < m < n]

(a)

(b)

(c)

(d)

Ans. (b)

Sol. For 1 – D box position of internal nodes is for n > 2

Where m = interger

For every integer of m and every value of n > 2

We get our positions

29. The number of CO stretching bands in the infrared spectrum of Fe(CO)₅ is

(a) 1

(b) 2

(c) 3

(d) 4

Ans. (b)

Sol.

One band equational CO and one band for axial CO.

30. The standard Gibbs free energy change for the reaction

at 2500 K is +118 kJ mol^–1.

The equilibrium constant for the reaction is

[Given: R = 8.314 J K^–1mol^–1]

(a) 0.994

(b) 1.006

(c) 3.42 × 10^–3

(d) 292.12

Ans. (c)

Sol.

= 118 × 10³ J mol^–1 = – 8.314 JK^–1mol^–1 × 2500 K ln k

K = 3.42 × 10^–3

31. Among the following, the reaction(s) that favor(s) the formation of the products at 25 ºC is/are

(a)

(b)

(c)

(d)

Ans. (a, b)

Sol.

32. Among the following, the correct statement(s) is/are:

(a) The first pK_a of malonic acid is lower than the pK_a of acetic acid while its second pK_a is higher than the pK_a of acetic acid.

(b) The first pK_a of malonic acid is higher than the pK_a of acetic acid while its second pK_a is lower than the pK_a of acetic acid.

(c) Both the first and the second pK_as of malonic acid are lower than the pK_a of acetic acid.

(d) Both the first and the second pK_as of malonic acid are higher than the pK_a of acetic acid.

Ans. (a)

Sol.

First is lower, second is higher

33. The compound(s) that participate(s) in Diels-Alder reaction with maleic anhydride is/are

(a)

(b)

(c)

(d)

Ans. (a, b)

Sol.

34. Among the following, the suitable route(s) for the conversion of benzaldehyde to acetophenone is/are

(a) CH₃COCl, anhydrous AlCl₃

(b) (i) HS(CH₂)₃SH, F₃B·OEt₂; (ii) n-BuLi; (iii) MeI; (iv) HgCl₂, CdCO₃, H₂O

(c) NaNH₂, MeI

(d) (i) MeMgBr; (ii) aq. acid; (iii) pyridiniumchlorochromate (PCC)

Ans. (c, d)

Sol.

35. The reaction

involve(s)

(a) migratory insertion

(b) change in electron count of Rh from 18 to 16

(c) oxidative addition

(d) change in electron count of Rh from 16 to 18

Ans. (a,b)

Sol.

1. Complex goes from 18 e^– to 16 e^–.

2. Migratory insertion is taking place.

36. The reason(s) for the lower stability of Si₂H₆ compared to C₂H₆ is/are

(a) silicon is more electronegative than hydrogen

(b) Si – Si bond is weaker than C – C bond

(c) Si – H bond is weaker than C – H bond

(d) the presence of low-lying d-orbitals in silicon

Ans. (b, c)

Sol. in Si – Si, then is bond formation via overlapping of 3p – 3p orbital which is weaker in compersion to C – C bond in which overlapping occur via 2p – 2p orbital overlapping & Si – H bond is polar in nature which make its less stable than C – H which is non polar& stable in nature.

37. For an N-atom nonlinear polyatomic gas, the constant volume molar heat capacity C_v,m has the expected value of 3(N – 1) R, based on the principle of equipartition of energy. The correct statement(s) about the measured value of C_v,m is/are

(a) The measured C_v,m is independent of temperature.

(b) The measured C_v,m is dependent on temperature.

(c) The measured C_v,m is typically lower than the expected value.

(d) The measured C_v,m is typically higher than the expected value.

Ans. (b, c)

Sol. According to the principle of equipartition of energy states that each degree of freedom in a molecule contributes (1/2) R to the molar heat capacity at constant volume (C_v,m) where R is ideal gas constant.

For a monlinear polyatomic gas with N atoms:

No. of degree of freedom = 3N – 6

Hence, C_v,m = 3 (N – 1) R

However, in reality, the measured value of C_v,m for polyatomic gases often deviates from the expected value due to various factor such as:

(i) Intermolecular interaction

(ii) Vibrational rotational coupling

(iii) Quantum effects

These deviations are more profround at low temperature.

Hence the correct statements are that the increased C_v,m is dependent on temperature and typically lower than expected value.

38. Zinc containing enzyme(s) is/are

(a) carboxypeptidase

(b) hydrogenase

(c) carbonic anhydrase

(d) urease

Ans. (a, c)

Sol.

(b) inhydrogenase Fe and Ni metal present

(d) in urease Ni metal present

39. The conversion of ICl to ICl⁺ involve(s)

(a) the removal of an electron from a^* molecular orbital of ICl

(b) an increase in the bond order from 1 in ICl to 1.5 in ICl⁺

(c) the formation of a paramagnetic species

(d) the removal of an electron from a molecular orbital localized predominantly on Cl

Ans. (a, b, c)

Sol.

40. The common point defect(s) in a solid is/are

(a) Wadsley defect

(b) Schottky defect

(c) Suzuki defect

(d) Frenkel defect

Ans. (b, d)

Sol. Point defects are the defects which exist at some lattice positions.

Schottky and Frenkel defect are point defects.

41. Among the following

the number of aromatic compounds is _______.

Ans. 5

Sol.

Number of aromatic compounds = 5

42. The number of stereoisomers possible for the major product formed in the reaction

is ________.

Ans. 2

Sol.

43. The number of signals observed in the ¹H NMR spectrum of the compound

is _______.

Ans. (3)

Sol. Number of signal

44. The reaction of 122 g of benzaldehyde with 108 g of phenylhydrazine gave 157 g of the product

The yield of the product is _______ %. (round off to the nearest integer)

Ans. (80)

Sol.

45. The B – B bond order in B₂ is _______.

Ans. (1)

Sol.

46. The number of unpaired electrons in [Co(H₂O)₆]²⁺ is _______.

Ans. 3

Sol. [Co(H₂O)₆]²⁺

The number of unpaired electrons in [Co(H₂O)₆]²⁺ is 3.

47. The number of significant figures in 5.0820 × 10² is _______.

Ans. 5

Sol. 5.0820 × 10²

Number of significant figures = 5

48. The d spacing for the first-order X-ray ( = 1.54 Å) diffraction event of metallic iron (fcc) at = 20.2º is ________ Å. (round off to three decimal places)

Ans. (4.391)

Sol.

= 1 × 1.54 Å = 2 × d × sin (10.1)

d = 4.391 Å

49. The volume fraction for an element in an fcc lattice is _____. (round off to two decimal places)

Ans. 0.74

Sol.

Z for FCC = 4

V = a³ (where a is edge length of cube)

also in FCC,

After putting the values, the volume fraction for an element in an fcc lattice is 0.74.

50. A steady current of 1.25 A is passed through an electrochemical cell for 1.5 h using a 12 V battery. The total charge, Q, drawn during this process is ______ Coulombs. (round off to the nearest integer).

Ans. (6750 C)

Sol. i = 1.25 A

t = 1.5 hr

Q = i × t = 1.25 × 1.5 × 3600

= 6750 C

51. The specific rotation of optically pure (R)-1-phenylethylamine is +40 (neat, 20 °C). A synthetic sample of the same compound is shown to contain 4:1 mixture of (S)- and (R)-enantiomers. The specific rotation of the neat sample at 20 °C is _________. (round off to the nearest integer)

Ans. -24º

Sol. (R) 1-phenylethylamine = + 40º

sample 4 : 1

S : R

Specific rotation of sample = ?

ee = 60% in (S)

= – 24º

52. The number of particles emitted in the nuclear reaction is _____.

Ans. (6)

Sol.

92 = 82 + 2x – y

92 – 82 = 2x – y

10 = 2x – y ... (1)

238 = 206 + 4x + 0

32 = 4x

= 8

10 = 2x – y

10 = 2 × 8 – y

10 – 16 = – y

1 – 6 = +4

y = 6

= 6

53. Iron is extracted from its ore via the reaction

Fe₂O₃ + 3 CO 2 Fe + 3 CO₂

The volume of CO (at STP) required to produce 1 kg of iron is ______ liters.

(round off to the nearest integer)

[Given: Atomic wt. of Fe = 56; assume STP to be 0 ºC and 1 atm]

Ans. (600)

Sol. Fe₂O₃ + 3CO 2Fe + 3CO₂

2 moles of Fe formed by 3 moles of CO

= 26.78 moles of CO

= 26.78 × 22.4 at STP

= 600 l

54. Total degeneracy (number of microstates) for a Ti³⁺ ion in spherical symmetry is ______.

Ans. 10

Sol. Ti³⁺ d¹

Number of microstate

55. A galvanic electrochemical cell made of Zn²⁺/Zn and Cu²⁺/Cu half-cells produces 1.10 V at 25 ºC. The ratio of [Zn²⁺] to [Cu²⁺] is maintained at 1.0. The for the reaction when 1.0 mol of Zn gets dissolved is ______ kJ. (round off to the nearest integer)

[Given: Faraday's constant = 96485 C mol^–1]

Ans. (– 212.3)

Sol. Eº = 1.1 V

= – nFEº

= – 2 × 96500 × 1.1

= – 212.3 kJ

56. At constant volume, 1.0 kJ of heat is transferred to 2 moles of an ideal gas at 1 atm and 298 K. The final temperature of the ideal gas is ______ K. (round off to one decimal place)

[Given: R = 8.314 J K^–1mol^–1]

Ans. (358)

Sol. At constant value (qp)_V =

= 1.0 kJ

= 1000 J

We know, DU = nC_v

C_v = molar heat capacity at constant volume

For monoatomic gas

For polyatomic gas C_v = 5/2 R

Since the gas is not specified, we'll assume that it's a monoatomic gas

{R = 8.314 JK^–1mol^–1}

= 60 K

Final temperature of ideal gas: = T₂ – T₁

60 = T₂ – 298

T₂ = 358 K

57. Two close lying bands in a UV spectrum occur at 274 nm and 269 nm. The magnitude of the energy gap between the two bands is _____ cm^–1. (round off to the nearest integer)

Ans. (678)

Sol.

= 37174.72 – 36496.35

= 678.37

= 678.4 = 678 cm^–1

58. The pH of an aqueous buffer prepared using CH₃COOH and CH₃COO^–Na⁺ is 4.80.

(round off to three decimal places)

[Given: pK_a of CH₃COOH in water is 4.75]

Ans. (0.122)

Sol.

Q = 10^0.05 = 1.122

= 0.122

59. At constant temperature, 6.40 g of a substance dissolved in 78 g of benzene decreases the vapor pressure of benzene from 0.125 atm to 0.119 atm.

The molar mass of the substance is _______ g mol^–1.

(round off to one decimal place)

[Given: Mol. wt. of benzene = 78 g mol^–1]

Ans. (126.9)

Sol.

6n + 6 = 125 n

119 n = 6

M = 126.9 g mole^–1

60. For a van der Waals gas, the critical temperature is 150 K and the critical pressure is 5 × 10⁶ Pa. The volume occupied by each gas molecule is _______ Å.

(round off to two decimal places)

[Given: R = 8.314 J mol^–1 K^–1, N_A = 6.023 × 10²³]

Ans. (12.941)

Sol.

= 12.941