GATE Chemistry 2017
Previous Year Question Paper with Solution.

1. Consider N particles at temperature T, pressure P, Volume V and chemical potential µ having energy E. The parameters that are kept constant for a canonical ensemble are

(a) N, V, T

(b) N, V, E

(c) N, P, T

(d) µ, V, T

Ans. (a)

Sol. For canonical ensemble N, V, T = constant

Correct option is (a)

2. For ortho – hydrogen, the nuclear wavefunction and the rotational quantum number, respectively, are

(a) antisymmetric and even

(b) symmetric and odd

(c) symmetric and even

(d) antisymmetric and odd

Ans. (b)

Sol. For ortho hydrogen,

Nuclear wave function symmetric

Rotational quantum number symmetric odd

Correct option is (b)

3. m1 and m2 are the slopes (dP/dT) of the solid – liquid equilibrium lines in the P – T phase diagrams of H2O and CO2, respectively. For P < 10 atm, the values of m1 and m2 are

(a) m1 > 0 and m2 > 0

(b) m1 > 0 and m2 < 0

(c) m1 < 0 and m2 < 0

(d) m1 < 0 and m2 > 0

Ans. (d)

Sol.

Slope of HO will be negative for s-l equilibrium line

Slope CO is positive for s-l equilibrium line

M1 < 0 and M2 > 0

Correct option is (d)

4. The rate constant of a reaction is 1.25 × 10–4 mol L–1 s–1. If the initial concentration of the reactant is 0.250 mol L–1, the total time (in second) required for complete conversion is __________

Ans. 2000

Sol. K = 1.25 × 10–4 mol L–1s–1

[A]0 = 0.250

Unit of K shows zero order reaction

[A]0 – [A] = Kt;

At completion of reaction [A] = 0

[A]0 = Kt

t = = 0.2 × 104; t = 2 × 103 sec.

Correct answer is (2000)

5. Consider an ideal gas of volume V at temperature T and pressure P. If the entropy of the gas is S, the partial derivative is equal to

(a)

(b)

(c)

(d)

Ans. (c)

Sol.

Correct option is (c)

6. The wavelength associated with a particle in one – dimensional box of length L is (n referes to the quantum number)

(a) 2L / n

(b) L / n

(c) nL

(d) L/2n

Ans. (a)

Sol.

Correct option is (a)

7. The dependence of rate constant k on a temperature T (in K) of a reaction is given by the expression

ln k = [(–5000 K)/T] + 10

The activation energy of the reaction (in kJ mol–1) is __________ (up to two decimal places)

Ans. 41.57

Sol. In K = – + 10

In K = ln A –

Ea = 5000 × 8.314; Ea = 41570 J

Ea = 41.57 kJmol–1

Correct answer is (41.57)

8. The lowest energy of a quantum mechanical one – dimensional simple harmonic oscillator is 300 cm–1. The energy (in cm–1) of the next higher level is +_________

Ans. 900

Sol. Lowest energy in simple harmonic oscillator is

En =

E1 = = 3 × = 3 × 300 cm–1 = 900 cm–1

Correct answer is (900)

9. The electronic ground state term for the chromium ion in [Cr(CN)6]4– is

(a) 3F

(b) 3H

(c) 3G

(d) 5D

Ans. (b)

Sol. [Cr(CN)6]4–, in this complex ion, oxidation state of Cr is +2 and its valence shell electronic configuration is 3d4. The CN ligands are strong, they therefore, cause [Cr(CN)6]4– ion,

ML = 4 + 1 = 5, H state

2S + 1 = 3

Ground state term = 3H

Correct option is (b)

10. The and ion exhibit intense ligand to metal charge transfer transition. The wavelengths of this transition follow the order

(a)

(b)

(c)

(d)

Ans. (c)

Sol. The and ions exhibit intense ligand to metal charge transfer transition. The energy required for electron transfer from p orbital of oxide ion to metal ion in these isoelectronic species decreases in the order

On moving from size of metal cation decreases because effective nuclear charge increases and energy of acceptor orbitals (d-orbital) decreases. Therefore energy of charge transfer decreases as

Hence, the wavelengths of this transition follow the order

Correct option is (c)

11. The lanthanide ion the exhibits color in aqueous solution is

(a) La (III)

(b) Eu (III)

(c) Gd (III)

(d) Lu (III)

Ans. (b)

Sol. If the electromagnetic radiations absorbed by a compond lie in UV-visible region then compound appears coloured

La3+ (4f0) colourless

Eu3+ (4f6) pale pink colour

Gd3+ (4f7) colourless

Lu3+ (4f14) colourless

Correct option is (b)

12. The hapticity of cycloheptatriene, (C7H8), in Mo(C7H8) (CO)3 is ___________

Ans. 6

Sol. According to Neutral atom method of 18 electron count

Mo 6e

3CO 6e

6 + x + 6 = 18

x = 18 – 12

x = 6

Hence, heptacity is 6

13. The vO–O resonance Raman stretching frequency (in cm–1) of the O2 coordinated to iron centre in oxyhemoglobin is nearly

(a) 1100

(b) 850

(c) 1550

(d) 1950

Ans. (a)

Sol. In oxy hemoglobin Fe is in +3 oxidation state and O2 is in O2

As oxygen accept electron in orbital hence, bond order get reduced and frequency decreases.

Since after binding to Fe in Hb bond between O – O become weaker comparison to free O – O bond in O2

There fore force constant k decreases and v stretching frequency would decrease

Correct option is (a)

14. The energy band diagram for magnesium is

(The hatched and unhatched regions in the figure correspond to filled and unfilled regions of the band, respectively.)

(a)

(b)

(c)

(d)

Ans. (d)

Sol. In Mg valence 3s is filled and it overlaps with empty 3p conduction hand

Correct option is (d)

15. P, F and I represent primitive, face – centered and body – centered lattices, respectively. The lattice types of NaCl and CsCl, respectively, are

(a) F and I

(b) F and P

(c) I and P

(d) P and I

Ans. (b)

Sol. For NaCl, number of formula units for unit cell

Na = Body centre + Edge centre

Z-Na+ = 1 × 1 + 12 × (1/4) = 1 + 3 = 4

Cl = Corner centre + face centre

Z-Cl = 8 × (1/8) + 6 / (1/2) = 1 + 3 = 4

Z = 4 FCC F

Cs = body centre = 1 × 1 = 1

Cl = corner = 8 × (1/8) = 1

CsCl, Z = 1 SCC P

Correct option is (b)

16. The characteristic feature of an electronic spin resonance (ESR) spectrum of frozen aqueous solution of CuSO4.5H2O at 77 K is

(a)

(b)

(c)

(d)

Ans. (a)

Sol. In CuSO4, 5H2O

Electronic configuration = 3d9 4s0

Last electron in orbital. So, g > g1

Correct option is (a)

17. The most suitable reagenet for the following transformation is

(a) Li / Liq. NH3

(b) PtO2 / H2

(c) LiAlH4

(d) B2H6

Ans. (a)

Sol.

Correct option is (a)

18. The major products M and N formed in the following reactions are

(a)

(b)

(c)

(d)

Ans. (c)

Sol.

(2 pyridone anion is alkylated and aminated mainly on nitrogen and is acylated on oxygen and reacts at ring C-atom in kolbe reaction)

Correct option is (c)

19. The 13C NMR spectrum of acetone – d6 has a signal at 30 ppm as a septet in the intensity ratio

(a) 1 : 6 : 15 : 20 : 15 : 6 : 1

(b) 1 : 3 : 6 : 7 : 6 : 3 : 1

(c) 1 : 2 : 3 : 5 : 3 : 2 : 1

(d) 1 : 3 : 7 : 10 : 7 : 3 : 1

Ans. (b)

Sol. Acetone-d6

multiplicity (2NI + 1)

(2 × 3 × 1 + 1)

7 (septet)

I = 3 (Non pascal)

Intensity pattern

1 : 3 : 6 : 7 : 6 : 3 : 1

Correct option is (b)

20. The major product formed in the following reaction is

(a)

(b)

(c)

(d)

Ans. (d)

Sol.

Correct option is (d)

21. The major product obtained in the following reaction is

(a)

(b)

(c)

(d)

Ans. (b)

Sol.

Correct option is (b)

22. In the two setp reaction sequence given below, the starting bis – sulfone acts as

(a) a dienophile and synthetic equivalent of acetylene

(b) a dienophile and synthetic equivalent of ethylene

(c) a dipolarophile and synthetic equivalent of acetylene

(d) a dipolarophile and synthetic equivalent of ethylene

Ans. (a)

Sol.

Correct option is (a)

23. The major product formed in the following photochemical reaction is

(a)

(b)

(c)

(d)

Ans. (b)

Sol.

This is Barton Reaction.

Correct option is (b)

24. The product formed in the following reaction is

(a)

(b)

(c)

(d)

Ans. (d)

Sol.

Correct option is (d)

25. The number of possible stereoisomers for cyclononene is ___________

Ans. 3

Sol.

Give superimposable mirror image.

Total steeoismers of cyclonone = 3

Correct answer is (3)

26. The mobility of a univalent ion in aqueous solution is 6.00 × 10–8 m2 s–1 V–1 at 300 K. Its diffusion coefficient at 300 K is X × 10–9 m2 s–1. The value of X is ________ (up to two decimal places)

Ans. 1.55

Sol. D = = 1552 × 10–12 = 1.552 × 10–9 m2s–1

X is 1.552

Correct answer is (1.55)

27. For the following consecutive first order reactions

the time (in seconds) required for Y to reach its maximum concentration (assumping only X is present at time t = 0) is __________ (up to two decimal places)

Ans. 1.576

Sol.

tmax =

tmax = 1.576 sec

Correct option is (1.576)

28. Under physiological conditions, the conversion of CO2 to bicarbonate ion by carbonic anhydrase enzyme (MW = 30,000 g mol–1) has a turnover number of 4.00 × 105 s–1. The minimum amount of enzyme (in µg) required to convert 0.44 g of CO2 to bicarbonate ions in 100 seconds is _________ (up to two decimal places)

Ans. 7.5

Sol. Rectant + Enzyme product

Turn over number =

= = 4 × 105 ⇒ x = 7.5 × 10–6g = (7.5 µg)

Correct answer is (7.5)

29. Assume 1, 3, 5 – hexatriene to be a linear molecule and model the electrons as particles in a one – dimensional box of length 0.70 nm. The wavelength (in nm) corresponding to the transition from the ground – state to the first excited – state is _______________.

Ans. 225 to 240

Sol.

Correct answer is (225 to 240)

30. The standard Gibbs free energy change of the reaction shown below is –2.7 kJ mol–1.

Sn(s) + Pb2+ = Sn2+ + Pb(s)

Given that E0(Pb2+/Pb) is –0.126 V, the value of E0(Sn2+/Sn) in V is ________ (up to two decimal places)

Ans. –0.14

Sol. Sn(s) + Pb2+ Sn2+ + Pb(s); n = 2

= –nf E0

0.0139 = –0.126 –

Correct answer is (–0.14)

31. The dissociative chemisorption of X2(g) one a metal surface follows langmuir adsorption isotherm. The ratio of the rate constants of the adsorption and desorption processes is 4.0 atm–1. The fractional surface coverage of X (adsorbed) at 1.0 atm pressure is ________ (up to two decimal places)

Ans. 0.67

Sol.

Correct answer is (0.67)

32. The ionic activity coefficients of Ca2+ and F are 0.72 and 0.28, respectively. The mean activity coefficient of CaF2 is __________ (up to two decimal places)

Ans. 0.39

Sol.

Correct answer is (0.39)

33. The angle of orientation (in degrees) of the angular momentum vector with respect to z – axis for I = 2 and state of H – atom is _________ (up to two decimal places)

Ans. 33.60 to 36.90

Sol.

Correct answer is (33.60 to 36.90)

34. The Gibbs free energy of mixing is denoted as mole of He, 3.0 moles of Ne and 2.0 moles of Ar are mixed at the same pressure and temperature. Assuming ideal gas behavior, the value of is ___________ (up to two decimal places)

Ans. 6.07

Sol. nHe = 1 mol nNe = 3 moles nAn = 2 moles

= 6{– 0.2986 – 0.3465 – 0.3662} = 6.067 = 6.07

Correct answer is (6.07)

35. represents a normalized molecular orbital constructed from two different atomic orbitals and that form an orthonormal set. The value of |c| is __________. (up to two decimal places)

Ans. 0.81

Sol.

for normalized

Correct answer is (0.81)

36. In cyclophosphazenes (NPX2)3 (X = F, Cl, Br and Me), the strength of P – N – bond varies with X in the order

(a) F > Cl > Br > Me

(b) Me > F > Cl > Br

(c) Br > Cl > F > Me

(d) Me > Br > Cl > F

Ans. (a)

Sol.

As the electronegativity of substituent increases. Energy of d-orbital decreases hence better interaction between 2p-orbital of nitrogen and 3d-orbital of phosphorus. Hence, strong the -bond.

Correct option is (a)

37. The structure type and shape of the polyhedral (skeletal) framework of the carborane Me2C2B10H10, respectively, are

(a) nido and dodecahedron

(b) closo and icosahedron

(c) nido and icosahedron

(d) closo and dodecahedron

Ans. (b)

Sol. Me2C2B10H10

Methyl is like hydrogen hence it is 1 electron donoar.

Hence, number of framework electron.

2CH = 6

10BH = 20

————– i.e. (n + 1) pair

26 = 13 pair

Hence, closo, also de to 12 vertex it has icosahedrum structure.

Correct option is (b)

38. If is the octahedral splitting energy and P is the electron pairing energy, then the crystal – field stabilization energy (CFSE) of [Co(NH3)6]2+ is

(a)

(b)

(c)

(d)

Ans. (c)

Sol. [Co(NH3)6]2+ ion In this complex ion, oxidation state of Co is +2 and its valence shell electronic configuration is 3d7.

Since, [Co(NH3)6]2+ has only in +2 oxidation state of metal NH3 acts as weak field ligand.

Electronic configuration

Crystal field spliting energy (CFSE) of [Co(NH3)6]2+

Correct option is (c)

39. The rates of substitution for the following reaction vary with L in the order

(a)

(b)

(c)

(d)

Ans. (d)

Sol. Trans effect of a group or Ligand (Spectator Ligands) coordinated to the metal cation is the tendency of that group to direct an incoming ligands to occupy the position trans to the group.

Trans effect of some ligands follow the order

In the given reaction,

Hence, the rate of substitution with L in the order

Correct option is (d)

40. The product formed in the reaction of MeMn(CO)5 with 13CO is

(a) (Me13CO)Mn(CO)5

(b) (MeCO)Mn(CO)5

(c) (MeCO)Mn(CO)4(13CO)

(d) (Me13CO)Mn(CO)4(13CO)

Ans. (c)

Sol.

18 electron complex

Correct option is (c)

41. For the following three alkenes, 1, 2, and 3, the rates of hydrogeneation using Wilkinson's catalyst at 20ºC vary in the order

(a) 1 > 3 > 2

(b) 1 > 2 > 3

(c) 2 > 1 > 3

(d) 2 > 3 > 1

Ans. (b)

Sol. Salient feature of Wilkinson's catalyst are

Rate of hydrogenation of terminal is greater than that of internal alkene.

Steric hindrance decrease the rate of hydrogenation

Rate of hydrogenation of cis alkene is greater than that of trans-alkene

Correct option is (b)

42. 210Bi undergoes decay to 1/8 of its initial amount in 15 days. The time required for its decay to 1/4 of its initial amount is __________ days (up to two decimal places)

Ans. 10.0029

Sol.

t = 0 [A]0

t = 15 days, [A] = [A]0

t = ? days, [A] = [A]0

Correct answer is (10.0029)

43. The metal ion and the macrocyclic skeleton present in the green pigment of plants, respectively, are

(a) Mg(II) and chloring

(b) Mg (II) and corrin

(c) Mn(II) and chlorin

(d) Mg(II) and porphine

Ans. (a)

Sol. Chlorophylls are complexes of Mg2+ with porphyrin ring in which one of the pyrrole rings has been reduced. A porphine ring with one double bond reduced is called a chlorin. Therefore, chlorophylls are the complexes of Mg2+ metal ion with substituted chlorin (macrocylic skeleton)

Correct option is (a)

44. The spinel structure of MgAl2O4 has cubic close packed arrangement of oxide ions. The fractions of the octahedral and tetrahedral sites occupied by cations, respectively, are

(a) 1/8 and 1/2

(b) 1/4 and 1/2

(c) 1/2 and 1/4

(d) 1/2 and 1/8

Ans. (d)

Sol. MgAl2O4 is a type of normal spinel

In normal spinel, Mg2+(A2+) ion occupy one eight of the tetrahedral voids and Al3+(B3+) ions

Occupy half(½) of the octahedral voids.

Correct option is (d)

45. The diffusion limiting current (Id) at a dropping mercury electrode for an aqueous Mg(II) solution of concentration 'c' (mol L–1) is 300 µA. If 'c' is increased by 0.1 mol L–1, Id increases to 900 µA. The value of 'c' (in mol L–1) is ___________ (up to two decimal places)

Ans. 0.05

Sol. Id = 300 µA at concnetration 'C'

C' = C + 0.1, Id' = 900 µA

Correct answer is (0.05)

46. The major product formed in the following reaction is

(a)

(b)

(c)

(d)

Ans. (c)

Sol.

Correct option is (c)

47. The product formed in the following photochemical reaction is

(a)

(b)

(c)

(d)

Ans. (d)

Sol.

Correct option is (d)

48. Among the following decahydroquinoline toluenesulfonates (Ts), the one that yields 9 – methylamino – E – non – 5 – enal as a major product upon aqueous solvolysis is

(a)

(b)

(c)

(d)

Ans. (c)

Sol.

Correct option is (c)

49. The product obtained in the following solvolysis reaction is

(a) a racemic mixture of trans 1, 2 – diacetoxycyclohexane

(b) enantiomerically pure trans 1, 2 – diacetoxycyclohexane

(c) racemic cis 1, 2 – diacetoxycyclohexane

(d) a mixture of cis and trans 1, 2 – diacetoxycyclohexane

Ans. (a)

Sol.

Correct option is (a)

50. The spectroscopic data for an organic compound with molecular formula C10H12O2 are given below. IR band around 1750 cm–1. 1H NMR 7.3 (m, 5H), 5.85 (q, 1H, J = 7.2 Hz), 2.05 (s, 3H), 1.5 (d, 3H, J = 7.2 Hz) ppm. the compound is

(a) methyl 2 – phenylpropionate

(c) 1 – (phenylethyl) acetate

(c) 2 – (phenylethyl) acetate

(d) methyl 3 – phenylpropionate

Ans. (b)

Sol. 1-(phenyl ethyl) acetate

1.5 (d3H, J = 7.2Hz) 5.85 (q1H.J = 72)

Correct option is (b)

51. The structure of the intermediate [P] and major product Q formed in the following reaction sequence are

(a)

(b)

(c)

(d)

Ans. (b)

Sol.

Correct option is (b)

52. Hydration of fumaric acid gives malic acid as shown below. Assume that addition of water takes place specific cally from A face or B face. The correct statement pertaining to stereochemistry of malic acid formed is

(a) addition specifically from A face gives S isomer of malic acid

(b) addition specifically from B face gives S isomer of malic acid

(c) addition specifically from A face gives R isomer of malic acid

(d) addition specifically from B face gives a racemic mixture of malic acid

Ans. (a)

Sol.

Correct option is (a)

53. Hydroboration of 2 – butyne with (C6H11)2BH yields the intermediate U, which on treatment with I2 and NaOMe at –78ºC, gives product V. The structure of U and V are

(a)

(b)

(c)

(d)

Ans. (d)

Sol.

Correct option is (d)

54. The structures of the major products W and X in the following synthetic scheme are

(a)

(b)

(c)

(d)

Ans. (d)

Sol.

Correct option is (d)

55. The major product Y and Z in the following reaction sequence are

(a)

(b)

(c)

(d)

Ans. (a)

Sol.

Correct option is (a)