GATE Chemistry 2015
Previous Year Question Paper with Solution.

1. Amongst the following the compound that DOES NOT act as a diene in Diels-Alder reaction is

(a)

(b)

(c)

(d)

Ans. (b)

Sol.

Correct option is (b)

2. An efficient catalyst for hydrogenation of alkenes is [Rh(PPh3)3Cl]. However, [Ir(PPh3)3Cl] does not catalyze this reaction, because

(a) PPh3 binds stronger to Ir than to Rh

(b) Cl binds stronger to Ir than to Rh

(c) PPh3 binds stronger to Rh than to Ir

(d) Cl binds stronger to Rh than to Ir

Ans. (a)

Sol. In catalytic cycle of hydrogenation of alkene

First step involve dissociation of PPh3 ligand from the catalyst to create vacant site.

On descending the group metal – ligand bond dissociation enthalpy increases for transition metal.

Correct option is (a)

3. Which of the following properties are characteristics of an ideal solution?

(a) (i) and (iv)

(b) (i) and (ii)

(c) (i) and (iii)

(d) (iii) and (iv)

Ans. (b)

Sol. For an ideal solution,

Correct option is (b)

4. Among the following compounds, the one that is non-aromatic, is

(a)

(b)

(c)

(d)

Ans. (a)

Sol.

COT has tub shape and is non-plannar hence non-aromatic

Correct option is (a)

5. Given the E° values for the following reaction sequence,

the computed value of E0 for (in volts) is _____________.

Ans. 1.66 to 1.70

Sol.

Correct option is (1.66 to 1.70)

6. The expression for the equilibirum constant (Keq) for the enzyme catalyzed reaction given below, is

(a)

(b)

(c)

(d)

Ans. (a)

Sol.

Correct option is (a)

7. The absorption spectrum of [Ti(H2O)6]3+ in solution comprises of a maximum with a shoulder. The reason for the shoulder is

(a) ligand-to-metal charge transfer (LMCT)

(b) metal-to-ligand charge transfer (MLCT)

(c) Jahn-Teller distortion

(d) nephelauxetic effect.

Ans. (c)

Sol. [Ti(H2O)6]3+,

, t2g unsymmetrically filled and it shows dynamic J.T.D., in the spectrum the shoulder appears due to J.T.D.

Correct option is (c)

8. The compound given below is a

(a) sesterterpene

(b) monoterpene

(c) sesquiterpene

(d) triterpene

Ans. (c)

Sol.

Hirsutene is a sesquiterpene molecular formulla C15H24. Having three isoprene units.

Correct option is (c)

9. The electrical conductivity of a metal

(a) Increase with increasing temperature

(b) decrease with increasing temperature

(c) is independent of temperature

(d) shows oscillatory behaviour with temperature

Ans. (b)

Sol. The electrical conducting of a metal decreases with increasing temperature.

Correct option is (b)

10. Which one of the following statements is INCORRECT?

(a) Frenkel defect is a cation vacancy and a cation interstitial

(b) Frenkel defect is an anion vacancy and a cation interstitial

(c) Density of a solid remains unchanged in case of Frenkel defects.

(d) Density of a solid decreases in case of Schottky defects.

Ans. (a)

Sol. Frenkel defect is an anion vacancy and a cation interstitial

Correct option is (a)

11. Among the given pH values, the O2 binding efficiency of hemoglobin is maximum at

(a) 6.8

(b) 7.0

(c) 7.2

(d) 7.4

Ans. (d)

Sol. The O2 bidning efficiency of haemoglobin is maximum at blood pH is 7.4.

Correct option is (d)

12. When the operator, operates on the function e–kx the result is

(a)

(b)

(c)

(d)

Ans. (a)

Sol.

Correct option is (a)

13.

From the above Carnot cycle undergone by an ideal gas, identify the processes in which the change in internal enery is NON-ZERO.

(a) I and II

(b) II and IV

(c) II and III

(d) I and IV

Ans. (b)

Sol.

In isothermal process,

In adiabatic process,

Correct option is (b)

14. Which one of the following defines the absolute temperature of a system?

(a)

(b)

(c)

(d)

Ans. (a)

Sol.

Correct option is (a)

15. The following conversion is an example of

(a) Arndt-Eistert homologation

(b) Mannich reaction

(c) Michael addition

(d) Chichibabin amination reaction

Ans. (b)

Sol.

Correct option is (b)

16. The compound with planr geometry is

(a) N(t–Bu)3

(b) NPh3

(c) NF3

(d) N(SiH3)3

Ans. (d)

Sol. Due to interaction in N(SiH3)3 it has a planar geometry.

Correct option is (d)

17. Reaction of benzaldehyde and p-methylbenzaldehyde under McMurry coupling conditions (TiCl3 and LiAlH4) gives a mixture of alkenes. The number of alkenes formed is_____________

Ans. 6 to 6

Sol.

Mixture of alkene will be .....................

(a)

When p-methyl benzaldehyde gives self mc-mury coupling reaction

When benzaldehyde and para methyl benzaldehye gives coupling reaction

Totoal nunber of mixture of alkene = 6

Correct option is (6 to 6)

18. The correct oder of reactivity of p-halonitrobenzenes in the following reaction is

(X = F, Cl, Br, I)

(a) p-chloronitrobenzene > p-iodonitrobenzene > p-fluoronitrobenzene > p-bromonitrobenzene

(b) p-fluoronitrobenzene > p-chloronitrobenzene> p-bromonitrobenzene > p-iodonitrobenzene

(c) p-iodonitrobenzene > p-bromonitrobenzene > p-chloronitrobenzene > p-fluoronitrobenzene

(d) p-bromonitrobenzene > p-fluoronitrobenzene > p-iodonitrobenzene > p-chloronitrobenzene

Ans. (b)

Sol. Electrophilic centre :

Electronegativity order F > Cl > Br > I

More electronegative element create more electrophilicity. Also, stabilizes the σ-complex negative charged

At more electrophilic centre. Nucleophilic attrack faster.

So, correct order, p-fluronitrobenzene > p-chloronitrobenzene > p-bromonitrobenzene > p-iodonitrobenzene

Correct option is (b)

19. The absolute of C2 and C3 in the following compound is

(a) 2R, 3S

(b) 2S, 3R

(c) 2S, 3S

(d) 2R, 3R

Ans. (d)

Sol.

At carbon number 2 (priority Acc. to CIP rule) At carbon number 3 (priority Acc. to CIP rule)

Correct option is (d)

20. For an ideal gas with molar mass M, the molar translational entropy at a given temperature is proportional to

(a) M3/2

(b) M1/2

(c) eM

(d) ln(M)

Ans. (a)

Sol. For an ideal gas with molar mass M, molar translational entropy.

for translational entropy,

Correct option is (a)

21. Tollen's test is NEGATIVE for

(a) mannose

(b) maltose

(c) glucose

(d) sucrose

Ans. (d)

Sol.

Correct option is (d)

22. The intense red color of [Fe(bpy)3]2+ (bpy = 2, 2' -bipyridine) is due to

(a) metal-to-ligand charge transfer (MLCT)

(b) ligand-to-metal charge transfer (LMCT)

(c) d-d transition

(d) inter-valence charge transfer (IVCT)

Ans. (a)

Sol. Electronic configuration of Fe2+ = [Ar]3d6 and bpy (2, 2'-bipyridine) is an aromatic ligand with low lying orbital, so metal (Fe2+) transfers its electron to system of the ligand due to which, its colour is intense red. (MLCT).

Correct option is (a)

23. The ease of formation of the adduct, NH3.BX3 (where X = F, Cl, Br) follows the order

(a) BBr3 < BCl3 < BF3

(b) BCl3 < BF3 < BBr3

(c) BF3 < BCl3 < BBr3

(d) BBr3 < BF3 < BCl3

Ans. (c)

Sol.

BBr3 > BCl3 > BF3

Correct option is (c)

24. Which one of the following plots represents an acceptable wavefunction?

(a)

(b)

(c)

(d)

Ans. (d)

Sol.

It is an acceptable wavefunction because function is single valued and continuous.

Correct option is (d)

25. The mass spectrum of a dihalo compound shows peaks with relative intensities of 1 : 2 : 1 corresponding to M, M + 2 and M + 4 (M is the mass of the molecular ion), respectively. The compound is

(a)

(b)

(c)

(d)

Ans. (a)

Sol.

In the mass spectrum of this compound the intensity of bromide is 1 : 2 : 1 because bromide has two isotropic i.e., 79Br and 81Br.

Correct option is (a)

26. The value of 'g' and the number of signals observed for the references standard, diphenylpicry lhydrazyl (DPPH), in the solid stae ESR spectrum are, respectively

(a) 2.0036 and 1

(b) 2.0036 and 3

(c) 2.2461 and 1

(d) 2.2416 and 3

Ans. (a)

Sol. The "g" value of diphenylpicrylhydrazyl (DPPH) is 2.0036 and ESR spectrum of DPPH in solid state gives one line.

Correct option is (a)

27. Solvolysis of the optically active compound X gives, mainly

(a)

(b)

(c)

(d)

Ans. (c)

Sol.

Correct option is (c)

28. The complexes K2 [NiF6] and K3 [CoF6] are

(a) both paramagnetic

(b) both diamagnetic

(c) paramagnetic and diamagnetic, respectively

(d) diamagnetic and paramagnetic, respectively

Ans. (d)

Sol. K2[NiF6] low spin

[NiF6]2–

x – 6 = –2

x = +4

Correct option is (d)

29. The tetrapeptide, Ala-Val-Phe-Met, on reaction with Sanger's reagent, followed by hydrolysis gives

(a)

(b)

(c)

(d)

Ans. (c)

Sol.

Correct option is (c)

30. For a gas phase unimolecular reaction at tempeature 298K, with a pre-exponential factor of 2.17×1013s–1, the entropy of activation (JK–1 mol–1) is ____________

Ans. 10.2 – 10.6

Sol.

31. The process given below follows the Langmuir adsorption isotherm

If denotes the surface converage and P denotes the pressure, the slope of the plot of 1/ versus

(a) 1/(Keq)2

(b) 1/Keq

(c) –1/Keq

(d) 1/(Keq)1/2

Ans. (d)

Sol.

Slop is

Correct option is (d)

32. The major product formed in the following reaction is

(a)

(b)

(c)

(d)

Ans. (d)

Sol.

Correct option is (d)

33. A liquid has vapor pressure of 2.02×103N m–2 at 293 K and heat of vaporization of 41 kJ mol–1. The boiling point of the liquid (in Kelvin) is _________.

Ans. 382 to 385 K

Sol. P1 = 2.02 × 103 Nm–2 ; P2 = 1 atm = 1.01 × 105 Pa

T1 = 293K ; T2 = ?

Applying Clausius Clapeyron equation

Correct option is (382 to 385 K)

34. The difference in the ground state energies (kJ/mol) of an electron in one-dimensional boxes of lengths 0.2 nm and 2nm is _________.

Ans. 896 to 900

Sol.

E1 – E2 = 896

Correct option is (896 to 900)

35. The major product formed in the following reaction is

(a)

(b)

(c)

(d)

Ans. (b)

Sol.

Correct option is (b)

36. The internal energy of an ideal gas follows the equation U = 3.5 PV + k, where k is a constant. The gas expands from an initial volume of 0.25 m3 to a final volume of 0.86 m3. If the initial pressure is 5 N m–2, the change in internal energy (in joules) is (given PV1.3 = constant) _________.

Ans. –1.38 to –1.39

Sol. For and ideal gas, U = 3.5 PV + K

or U = 3.5 RT + K

dU = 3.5 R dT

= 3.5 R (T2 – T1)

V1 = 0.25 m3 P1 = 5 Nm–2 PV1.3 = constant

V2 = 0.86 m3 = ?? = 1.3

At initial state, P1V1 = RT1

T1 = = 0.1503 K

Since expansion is adiabatic,

T2 = 0.1035 K

= 3.5 R(T2 – T1) = 3.5 × 8.314 (0.1035 – 0.1503)

= –1.36 J

Correct option is (–1.38 to –1.39)

37. One mole of a substance is heated from 300K to 400K at contant pressure. The Cp of the substance is given by, Cp (JK–1 mol–1) = 5 + 0.1T. The change in entropy, in JK–1 mol–1, of the sustance is _________.

Ans. 11.3 to 11.5

Sol.

= 11.438 JK–1 mol–1

Correct option is (11.3 to 11.5)

38. The solubility product of AgBr(s) is 5×10–13 at 298K. If the standard reduction potential of the half-cell, is 0.07V, the standard reduction potential (in volts) is _________.

Ans. 0.79 to 0.82

Sol.

Correct option is (0.79 to 0.82)

39. The most suitable reagent (s) to effect the following transformed is

(a) N2H4, KOH heat

(b) TsNHNH2, CF3 COOH

(c) LiAlH4

(d) Na, liq. NH3

Ans. (a)

Sol.

Correct option is (a)

40. Ammonolysis of S2Cl2 in an inert solvent gives

(a) S2N2

(b) S2N2Cl

(c) S2N2H4

(d) S4N4

Ans. (d)

Sol. S2Cl2 + NH3 N4S4 + NH4Cl + S8

Correct option is (d)

41. The mean ionic activity coefficient of 0.001 molal ZnSO4 (aq) at 298K according to the Debye-Huckel limiting law is (Debye-Huckel constant is 0.509 molal–½ _________.

Ans. 0.73 to 0.75

Sol.

Correct option is (0.73 to 0.75)

42. Identify the function of hemocyanin and the metal responsible for it

(a) O2 transport and Fe

(b) O2 transport and Cu

(c) electron transport and Fe

(d) electron transport and Cu

Ans. (b)

Sol. Hemocyanin is a copper containing protein which is responsible for oxygen transport in some invertibrates.

Correct option is (b)

43. The point group of IF7 is

(a) D6h

(b) D5h

(c) C6v

(d) C5v

Ans. (b)

Sol.

Correct option is (b)

44. The limiting currect (in µA) from the reduction of 3×10–4 M Pb2+, using a dropping mercury electrode (DME) with characteristics, m = 3.0 mg s–1 and t = 3s, is (diffusion coefficient of Pb 2+ = 1.2×10–5 cm2 s–1)____.

Ans. 3.5 to 3.8

Sol. Ilkovic Equation:

id = 708 n D1/2 m2/3 c t1/6

where id = µA, D = cm2/s, m = mg/s, t = sec., c = m moles/L, n = no. of electron

id = 708 × 2 × (1.2 × 10–5)1/2 × 32/3 × 3 × 10–4 × 1000 × 31/6 (1M = 1000 m mol/L)

= 1416 × 3.46 × 10–3 × 2.078 × (3 × 10–4 × 103) × 1.2 = 36651.1 × 10–4

= 3.66 µA

3.7 µA

Correct answer is 3.5 to 3.8

45. Identify X in the reaction,

(a) cis – [PtCl2(NH3)2]

(b) trans – [PtCl2(NH3)2]

(c) [PtCl(NH3)3]+

(d) [PtCl3(NH3)]

Ans. (b)

Sol. Synthesis of trans-[Pt(NH3)2 Cl2] is carried out by the treating [Pt(NH3)4]2+ with Cl–1.

Correct option is (b)

46. The major products, K and L formed in the following reactions are

(a)

(b)

(c)

(d)

Ans. (b)

Sol.

Correct option is (b)

47. The major product formed in the following reaction is

(a)

(b)

(c)

(d)

Ans. (d)

Sol.

Correct option is (d)

48. The percent transmittance of 8×10–5M solution of KMnO4 is 39. when measured at 510 nm in a cell of path length of 1cm. The absorbance and the molar extinction coefficient (in M–1 cm–1) of this solution are, respectively

(a) 0.30 and 4500

(b) 0.35 and 4800

(c) 0.4 and 5000

(d) 0.48 and 5200

Ans. (c)

Sol. %T = 39.8 C = 8 × 10–5 M

Correct option is (c)

49. The rotational partition function of a diatomic molecule with energy levels corresponding to J = 0, 1, is (where, e is a constant)

(a)

(b)

(c)

(d)

Ans. (b)

Sol.

we know,

ERot = BJ (J + 1)

for J = 0

g0 = 2J + 1)

g0 = 1

for J = 1

g1 = (2 J + 1) = 3

where = same constant.

Correct option is (b)

50. When one CO group is replaced by PPh3 in [Cr(CO)6], which one of the following statement is TRUE?

(a) The Cr-C bond length increases and CO bond length decreases

(b) The Cr-C bond length decreases and CO bond length decreases

(c) The Cr-C bond length decreases and CO bond length increases

(d) The Cr-C bond length increases and CO bond length increases

Ans. (c)

Sol. The ligand PPh3 is strong σ-donor and weak π-acceptor than CO, hence, it will supply electron density on Cr due to which back donation increases, therefore Cr–C bond length decreases and C–O bond length increases.

Correct option is (c)

51. The number of possible stereoisomers obtained in the following reaction is ___________.

Ans. 8

Sol.

Possible stereoisomers = 23 = 8

Correct answer is (8)

52. The major product formed in the following reaction is

(a)

(b)

(c)

(d)

Ans. (d)

Sol. NBS = N-Bromosuccinimide =

Correct option is (d)

53. The Beckmann rearrangement of a bromoacetophenone oxime (C8H8BrNO) given a major product having the following 1HNMR : 9.89 (s, 1H), 7.88 (s, 1H), 7.45 (d, 1H, J = 7.2 Hz), 7.17 (m, 1H), 7.12 (d, 1H, J = 7.0 Hz), 2.06 (s, 3H). The structure of the product is.

(a)

(b)

(c)

(d)

Ans. (a)

Sol.

Correct option is (a)

54. The distance between two successive (110) planes in a simple cubic lattice with lattice parameter 'a' is

(a)

(b)

(c)

(d)

Ans. (d)

Sol.

Correct option is (d)

55. The potential energy (PE) versus reaction coordinate diagrams for electron transfer reactions with rate constants k1, k2 and k3 are given below. The increasing order of the rate constants is

(a) k2 < k3 < k1

(b) k2 < k1 < k3

(c) k3 < k2 < k1

(d) k3 < k1 < k2

Ans. (d)

Sol. The order of increasing rate constant is

k3 < k1 < k2

Correct option is (d)