GATE Exam 2020 Chemistry (CY) Question Paper With Answer Key


CY: Chemistry

GA-General Aptitude

Q1 – Q5 carry one mark each.

1. While I agree _____ his proposal this time, I do not often agree _____ him.

(A)  to, with

(B)  with, to

(C)  with, with

(D)  to, to

Answer: (A)

2. The recent measures to improve the output would _______ the level of production to our satisfaction.

(A)  increase

(B)  decrease

(C)  speed

(D)  equalise

Answer: (A)

3. Select the word that fits the analogy:

White : Whitening : Light: ______

(A)  Lightning

(B)  Lightening

(C)  Lighting

(D)  Enlightening

Answer: (B)

4. In one of the greatest innings ever seen in 142 years of Test history, Ben Stokes upped the tempo in a five-and-a-half hour long stay of 219 balls including 11 fours and 8 sixes that saw him finish on a 135 not out as England squared the five-match series.

Based on their connotations in the given passage, which one of the following meanings DOES NOT match?

(A)  upped = increased

(B)  squared = lost

(C)  tempo = enthusiasm

(D)  saw = resulted in

Answer: (B)

5. There are five levels {P, Q, R, S, T} in a linear supply chain before a product reaches customers, as shown in the figure.

At each of the five levels, the price of the product is increased by 25%. If the product is produced at level P at the cost of Rs. 120 per unit, what is the price paid (in rupees) by the customers?

(A)  187.50

(B)  234.38

(C)  292.26

(D)  366.21

Answer: (D)

Q6 – Q10 carry two marks each.

6. Climate change and resilience deal with two aspects – reduction of sources of non-renewable energy resources and reducing vulnerability of climate change aspects. The terms ‘mitigation’ and ‘adaptation’ are used to refer to these aspects, respectively.

Which of the following assertions is best supported by the above in information?

(A)  Mitigation deals with consequences of climate change.

(B)  Adaptation deals with causes of climate change.

(C)  Mitigation deals with actions taken to reduce the use of fossil fuels.

(D)  Adaptation deals with actions taken to combat gree-house gas emissions.

Answer: (C)

7. Find the missing element in the following figure.

(A)  d

(B)  e

(C)  w

(D)  y

Answer: (A)

8. It was estimated that 52 men can complete a strip in a newly constructed highway connecting cities P and Q in 10 days. Due to an emergency, 12 men were sent to another project. How many number of days, more than the original estimate, will be required to complete the strip?

(A)  3 days

(B)  5 days

(C)  10 days

(D)  13 days

Answer: (A)

9. An engineer measures THREE quantities X, Y and Z in an experiment. She finds that they follow a relationship that is represented in the figure below : (the product of X and Y linearly varies with Z)

Then, which of the following statements is FALSE?

(A)  For fixed Z; X is proportional to Y

(B)  For fixed Y; X is proportional to Z

(C)  For fixed X; Z is proportional to Y

(D)  XY/Z is constant

Answer: (A)

10. The two pie-charts given below show the data of total students and only girls registered in different streams in a university. If the total number of students registered in the university is 5000, and the total number of the registered girls is 1500; then, the ratio of boys enrolled in Arts to the girls enrolled in Management is ______.

(A)  2:1

(B)  9:22

(C)  11:9

(D)  22:9

Answer: (D)

CY: Chemistry

Q1 – Q25 carry one mark each.

1. Among the following, the suitable reagents for the given transformation is:

(A)  H2, Pd/C

(B)  H2N-NH2/KOH, ∆

(C)  NaBH4/CeCl3∙7H2O

(D)  Li/Liq. NH3

Answer: (C)

2. Major product formed in the following reaction sequence is:

Answer: (C)

3. Major product formed in the following reaction is:

Answer: (A)

4. Major product formed in the following transformation is:

Answer: (C)

5. Absolute stereochemistry of the given compound is:

(A)  4aR, 8aS

(B)  4aR, 8aR

(C)  4aS, 8aS

(D)  4aS, 8aR

Answer: (D)

6. In the following reaction sequence,

the major product P and Q are :

Answer: (C)

7. Major product formed in the given reaction is:

Answer: (B)

8. The CORRECT statement regarding the substitution of coordinated ligands in Ni(CO)4 and CO(NO)(CO)3 is:

(Given Co―N―O bond is nearly linear; atomic numbers of Co and Ni are 27 and 28, respectively)

(A)  Ni(CO)4 and Co(NO)(CO)3 follow associative and dissociative pathways, respectively.

(B)  Ni(CO)4 and Co(NO)(CO)3 follow dissociative and associative pathways, respectively.

(C)  Both Ni(CO)4 and Co(NO)(CO)3 follow associative pathway.

(D)  Both Ni(CO)4 and Co(NO)(CO)3 follow dissociative pathway.

Answer: (B)

9. The CORRECT statement about hexagonal boron nitride is :

(A)  It is a good electrical conductor.

(B)  It has same layer stacking as that of graphite.

(C)  It is reactive towards fluorine.

(D)  It has lower thermal stability in air compared to that of graphite.

Answer: (C)

10. In oxyhemocyanin, the coordination number, mode of oxygen binding, color and the net magnetic behavior of copper ions, respectively are:

(Given: atomic number of Cu is 29)

(A)  Four, μ-η11-O2, colorless and paramagnetic.

(B)  Five, μ-η22-O2, colorless and paramagnetic.

(C)  Five, μ-η22-O22, blue and diamagnetic.

(D)  Four, μ-η11-O22, blue and diamagnetic.

Answer: (C)

11. Among the following species, the one that has pentagonal shape is:

(Given: atomic numbers of O, F, S, I and Xe are 8, 9, 16, 53 and 54, respectively)

(A)  XeOF4

(B)  IF5

(C)  [SF5]

(D)  [XeF5]

Answer: (D)

12. A solution containing a metal complex absorbs at 480 mm with molar extinction coefficient of 15,000 L mol1 cm1. If the path length of the cell is 1.0 cm and transmittance is 20.5%, the concentration (in mol L1) of the metal complex is:

(A)  1.37 × 105

(B)  2.29 × 105

(C)  4.59 × 105

(D)  8.75 × 105

Answer: (C)

13. Among the following linear combination of atomic orbitals, the CORRECT representation of the lowest unoccupied π-molecular orbital of butadiene is:

(A)  Ψ = −0.372 ϕ1 + 0.602 ϕ2 – 0.602 ϕ3 + 0..372 ϕ4

(B)  Ψ = 0.602 ϕ1 – 0.372 ϕ2 – 0.372 ϕ3 + 0.602 ϕ4

(C)  Ψ = 0.602 ϕ1 + 0.372 ϕ2 – 0.372 ϕ3 – 0.602 ϕ4

(D)  Ψ = 0.372 ϕ1 + 0.602 ϕ2 + 0.602 ϕ3 + 0.372 ϕ4

Answer: (B)

14. The activity of ‘m’ molal CuSO­4 solution can be expressed in terms of its mean activity coefficient (γ±) as:

(A)  m2γ±2

(B)  4m3γ±3

(C)  16m4γ±4

(D)  108 m5γ±5

Answer: (A)

15. The character table for a pyramidal AB3 molecule of C3v point group is given below:

The reducible representation of pyramidal AB3 is

The CORRECT option representing all the normal Raman active modes of pyramidal AB3 is :

(A)  A1 + A2 + 2E

(B)  3E

(C)  3A1 + A2 + E

(D)  2A1 + 2E

Answer: (D)

16. In the following reaction,

the number of peaks exhibited by the major product P in its broadband proton decoupled 13C NMR spectrum is_______

Answer: (8.0 to 8.0)

17. Among the following,

the total number of aromatic species is________

Answer: (4.0 to 4.0)

18. The maximum number of microstates of d2 electronic configuration is_________

Answer: (45 to 45)

19. In a uranium recovery process, an aqueous solution of uranyl ion is evaporated, dried in air at 400°C and subsequently reduced with hydrogen at 700°C to obtain a uranium compound (X). The oxidation state of uranium in X is __________

(Given : atomic number of U is 92)

Answer: (4 to 4)

20. For a cubic crystal system, the powder X-ray diffraction pattern recorded using Cu Kα source (λ = 1.54 Å) shows a peak at 33.60° (2θ) for (111) plane. The lattice parameter ‘a’ (in Å, rounded off to two decimal places) is _________

Answer: (4.60 to 4.64)

21. In an NMR spectrometer operating at a magnetic field strength of 16.45 T, the resonance frequency (in MHz, rounded off to one decimal place) of 19F nucleus is ________

(Given : g factor of 19F = 5.255; βN = 5.05 × 1027 J T1; h = 6.626 × 1034 J s)

Answer: (658 to 659)

22. When three moles of helium is mixed with one mole of neon at constant temperature and pressure (25 °C, 1 atm), the entropy of mixing (in J K1, rounded off to two decimal places) is ________

(Given : R = 8.314 J K1 mol1)

Answer: (18.60 to 18.80)

23. At 25°C, the emf(in volts, rounded off to three decimal places) of the cell, Ag | AgBr(s) | Br (a = 0.20), Cu2+ (a = 0.48), Cu+(a = 0.24) | Pt is _______

(Given : The standard emf of the cell is 0.082 V; R = 8.314 J K1 mol1; F = 96500 C mol1)

Answer: (0.058 to 0.060)

24. For an enzyme catalyzed reaction, the plot of inverse of initial rate against inverse of initial substrate concentration is linear with slope 0.16 s and intercept 2.12 mol1 L s. The estimated value of Michaelis constant (in mol L1, rounded off to two decimal places is ________

Answer: (0.07 to 0.08)

25. Fluorescence quantum yield and fluorescence lifetime of a molecule are 0.4 and 5 × 109 s, respectively. If the fluorescence decay rate constant is Y × 107 s1, t he value of Y (rounded off to nearest integer) is _________

Answer: (8 to 8)

Q26 – Q55 carry two marks each.

26. Major product formed in the following reaction sequence is:

Answer: (C)

27. Major products P and Q, in the given reaction sequence, are:

Answer: (B)

28. Major products P and Q, formed in the reactions given below, are:

Answer: (C)

29. A compound with molecular formula C10H12O12 showed a strong IR band at ~ 720 cm1 a peak at m/z 122 in the mass spectrum and the following 1H NMR signals: δ1 – 8.0 (2H, m), 7.6 – 7.5(1H, m), 7.5 – 7.3 (2H, m), 4.3(2H, t), 1.8 (2H sextet) and 1.0 (3H, t). The structure of the compound is:

Answer: (B)

30. Major product formed in the following synthetic sequence is:

Answer: (A)

31. The CORRECT statement with respect to the stereochemistry of α-hydroxy acids P and Q formed in the following reactions is:

(A)  Both P and Q are formed with retention of configuration.

(B)  Both P and Q are formed with inversion of configuration.

(C)  P is formed with retention of configuration and Q with inversion of configuration.

(D)  P is formed with inversion of configuration and Q with retention of configuration.

Answer: (D)

32. The rate of solvolysis of the given compounds is in the order

(A)  T > R > Q > S > P

(B)  Q > T > R > P > S

(C)  R > T > Q > S > P

(D)  T > Q > R > P > S

Answer: (A)

33. In the following reaction sequence, the major products Q and R are:

Answer: (B)

34. In the electronic absorption spectrum of an aqueous solution of [Ni(NH3)6]2+, a very weak band is observed between the bands due to the transitions 3A2g3T2g and 3A2g3T1g(F). The transition responsible for the very weak band is

(Given: atomic number of Ni is 28)

(A)  3A2g1T1g

(B)  3A2g1T2g

(C)  3A2g1Eg

(D)  3A2g1A2g

Answer: (C)

35. The experimental magnetic moment (3.4 BM) of a hydrated salt of Eu3+ at 27°C is significantly different from the calculated value. The difference is due to

(Given: atomic number of Eu is 63)

(A)  population of electrons at higher J level(s) via thermal excitation.

(B)  strong ligand field splitting of f-orbitals.

(C)  strong spin-orbit coupling.

(D)  pairing of electrons in f-orbitals.

Answer: (A)

36. The CORRECT combination of L1 and L2 among H, NO, MeCH2 and CO, that will satisfy the 18 electron rule for both metal centers in the following neutral molecule, is

(Given: atomic number of Ru is 44)

(A)  H, NO

(B)  MeCH2, NO

(C)  MeCH2, CO

(D)  H, CO

Answer: (C)

37. In the following reaction sequence,

the structure of B is

(Given: atomic number of Mo is 42)

Answer: (D)

38. The following table lists the reaction/conversion catalyzed by metalloenzymes.

The correct combination is

(A)  P-II; Q-I; R-III; S-IV

(B)  P-IV; Q-III; R-II; S-I

(C)  P-II; Q-III; R-IV; S-I

(D)  P-I; Q-IV; R-III; S-II

Answer: (C)

39. The fission of  with thermal neutron is represented below.

 are the primary fission fragment pair, which undergo series of radioactive decay to form stable nuclei X3 and X4 (chain enders). The X3 and Y4, respectively are:





Answer: (B)

40. The CORRECT ‘voltage (E) versus time’ excitation signal used in cyclic voltammetry is

Answer: (C)

41. The hydrogen-like radial wave function of the 3s orbital is given as

where ρ = 2Zr/a0; Z = atomic number, r = distance from the nucleus and a0 = Bohr radius. Positions of the radial nodes (in  units of a0) of the 3s orbital are at





Answer: (C)

42. ∆Gf0 and ∆Hf0 for Fe(g) are 370.7 kJ mol1 and 416.3 kJ mol1 at 298 K, respectively. Assuming ∆Hf0 is constant in the interval 250 K to 375 K, ∆Gf0 (rounded off to the nearest integer) for Fe(g) at 375 K is:

(A)  359 kJ mol1

(B)  338 kJ mol1

(C)  325 kJ mol1

(D)  310 kJ mol1

Answer: (A)

43. Adsorption of N2 on TiO2 was carried out at 75 K. A plot of  gives a straight line with an intercept, 4.0 × 106 mm3 and slope, 1.0 × 103 mm3. The volume (rounded off to the nearest integer) corresponding to the monolayer coverage is:

(A)  996 mm3

(B)  785 mm3

(C)  690 mm3

(D)  555 mm3

Answer: (A)

44. Among the following sets,

the total number of set(s) of diastereomeric pair(s) is _______

Answer: (4.0 to 4.0)

45. Among the following.

the total number of compounds showing characteristic carbonyl stretching frequency less than 1700 cm1 in their IR spectra is _______

Answer: (3.0 to 3.0)

46. Consider the AgX crystallizes in rock salt structure. The density of AgX is 6477 kg/m3 and unit cell length is 577.5 pm. Atomic weight of Ag is 107.87 g mol1. The atomic weight of X (in g mol1, rounded off to two decimal places) is _______

Answer: (79.00 to 81.00)

47. The total number of g|| lines expected in the EPR spectrum of a solution of bis(salicylaldimine) copper(II) having pure 63Cu and 14N at 77 K is ________

(Given: I values of 63Cu, 14N and 1H are 3/2, 1 and 1/2, respectively)

Answer: (60 to 60)

48. Among the following,

[B12H12]2, [Ni5(CO)­12]2, [C2B9H11]2, Rh6(CO)16, Os6(CO)20, B5H11, B6H10 the total number of species having nido structure is________

(Given : atomic numbers of H, B, C, O, Ni, Rh and Os are 1, 5, 6, 8, 28, 45 and 76, respectively)

Answer: (3 to 3)

49. The frequency (in cm1, rounded off to two decimal places) for pure rotational line in the spectrum of NO molecule due to change in the quantum number from J = 1 to J = 2 is _______

(Given: Moment of inertia of NO = 1.6427 × 1046 kg m2; h = 6.626 × 1034 J s; c = 3 × 108 m/s)

Answer: (6.80 to 6.82)

50. The % error (rounded off to two decimal places) in the ground state energy of a particle in a one dimensional box of length ‘a’ described by a trial variation function φ = x(a – x), where 0 ≤ x ≤ a, is ________

(Given: The true ground state energy of the above system is h2/8ma2

Answer: (1.22 to 1.44)

51. Assuming no interaction between vibrational and rotational energy levels in HF, the frequency (in cm1, rounded off to the nearest integer) of the R branch line originating from J = 4 in its IR spectrum is ________

(Given: Rotational constant of HF = 19.35 cm1  

Answer: (4332 to 4332)

52. The van der Waals constants a and b for gaseous CO are given as 1.49 L2 atm mol2 and 0.0399 L mol1, respectively. The fugacity (in atm, rounded off to two decimal places) of CO at 35°C and 95 atm is ______

(Given: R = 0.082 L atm K−1 mol−1)

Answer: (88.11 to 88.60)

53. At 30°C, the vapor pressure and density of a 1.0 M aqueous solution of sucrose are 31.207 mm Hg and 1.1256 g/mL, respectively. If the vapor pressure of pure water at 30°C is 31.824 mm Hg, the activity coefficient (rounded off to three decimal places) of water in the given solution is _______

(Given: The molar mass of sucrose = 342.3 g mol1)

Answer: (1.002 to 1.004)

54. For the ring opening reaction of cyclopropane to propene at 25°C, the pre-exponential factor is 4.3 × 1015 s1. The entropy of activation (in J K1 mol1, rounded off to two decimal places) is _______.

(Given: h = 6.626 × 1034 J s; kB = 1.38 × 1023 J K1; R = 8.314 J K1 mol1)

Answer: (46.00 to 46.10)

55. In a reaction, reactant X is converted to products Y and Z consecutively with rate constants 6.0 × 102 min1 and 9.0 × 103 min1, respectively. If the initial amount of X is 12.5 moles, the number of moles (rounded off to one decimal place) of Y formed after 10 minutes is ________

Answer: (5.3 to 5.5)

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