PYQ 2009 - VedPrep

GATE Chemistry 2009
Previous Year Question Paper with Solution.

1. The ³¹P NMR spectrum of P₄S₃ consists of

(a) a singlet

(b) a doublet and a triplet

(d) two doublets.

Ans. (c)

Sol. P₄S₃

Correct option is (c)

2. The geometry around the centrla atom in CIF₄⁺ is

(a) square planar

(b) square pyramidal

(d) trigonal bipyramidal

Ans. (d)

Sol.

3. The correct statement about the Cu-N bond distances in [Cu(NH₃)₆]²⁺ is

(a) all the bond distances are equal

(b) the axial bonds are longer than the equatorial ones

(d) all the bond distances are unequal

Ans. (b)

Sol. In [Cu(NH₃)₆]²⁺, the geometry is distorted octahedral due to Jahn-Teller distortion and axial bond distances are larger than equatorial bond distances.

Correct answer is (b)

4. The reaction of phosgene with an excess of NH₃ produces

(a) HN = C = O

(b) H₂N – C (Cl) = O

(d) (H₂N)₂CCl₂

Ans. (c)

Sol. COCl₂ + 4NH₃ CO (NH₂)₂ + 4NH₄Cl

Phosgene

Correct option is (c)

5. The number of metal–metal bonds in [(C₅H₅) Fe (CO)₂]₂ is

(a) zero

(b) one

(d) three

Ans. (b)

Sol. [(C₅H₅) Fe (CO)₂]₂

TVE = 2Fe = 8 × 2 = 16 electron

2Cp = 5 × 2 = 10 electron

4CO = 4 × 2 = 8 electron

Toral = 34 electron

B = 18 × n – TVE

n = number of metal = 18 × 2 – 34 = 2

= Number of M – M bond = = 1

Correct option is (b)

6. The coordination number of the Ba²⁺ ions in barium fluoride is 8. The coordination number of the fluorie ion is:

(a) 8

(b) 4

(d) 2

Ans. (b)

Sol. In BaF₂ molecule, the coordination number Ba²⁺ is 8 and coordination number fluoride is 4.

Correct option is (b)

7. In the transformation of oxyhemoglobin to deoxyhemoglobin

(a) Fe²⁺ in the low spin state changes to Fe²⁺ in the high spin state

(b) Fe²⁺in the low spin state changes to Fe³⁺ in the low spin state.

(d) Fe²⁺ in the high spin state changes to Fe³⁺ in the high spin state.

Ans. (a)

Sol. The transformation of oxydemoglobin to deoxyhemoglobin Fe²⁺ involves change in low spin state to high spin state.

In deoxyhemoglobin, Fe²⁺ is in high spin state.

In oxyhemoglobin, iron of heme group bind with oxygen molecule, and become low spin

Correct option is (a)

8. For the compound

the stereochemical notations are

(a) 2Z, 4R

(b) 2Z, 4S

(d) 2E, 4S

Ans. (d)

Sol.

9. The compound is

(a) aromatic and has high dipole moment

(b) aromatic and has no dipole moment

(d) anti-aromatic and has no dipole moment.

Ans. (a)

Sol.

10. In the reaction,

the major product X is:

(a)

(b)

(c)

(d)

Ans. (b)

Sol.

11. In the reaction

the major product X and Y are

(a)

(b)

(c)

(d) None of these

Ans. (b)

Sol.

12. In the reaction

the major product X is:

(a)

(b)

(c)

(d)

Ans. (c)

Sol.

Note : stablised phosphorous ylide form trans alkene.

Correct option is (c)

13. The most suitable reagent combination to bring out the following transformation

(a) PhCOCl and pyridine

(b) DCC and PhCOOH

(d) EtOOC–N=N–COOEt, PPh₃ and PhCOOH

Ans. (d)

Sol.

14. In the two steps reaction sequence:

the major product Y is:

(a)

(b)

(c)

(d)

Ans. (a)

Sol.

15. Among the following the system that would require the least amount of thermal energy to bring its temperature to 80ºC.

(a) 200 gm of water at 40°

(b) 100 gm of water at 20°C

(d) 300 gm of water at 30°C.

Ans.

Sol. q =

(a) q = 200 C_S (80 – 40)

q = 8000 C_S

(b) q = 100 C_S (80 – 20)

q = 6000 C_S

q = 4500 C_S

(d) q = 300 C_S (80 – 30)

= 15000 C_S

Correct option is (c)

16. Among the following, the reaction that is accompanied by a decrease in the entropy is

(a)

(b)

(c)

(d)

Ans. (a)

Sol. If decrease in entropy.

In option (a)

Correct option is (a)

17. The number of degrees of freedom of a system consisting of solid sucrose in equilibrium with an aqueous solution of sucrose is

(a) 0

(b) 1

(d) 3

Ans. (c)

Sol. Sucrose(s) Sucrose (aq)

It is a non-reactive system.

Therefore, C = number of chemical constitute which is 2 here C = 2.

Correct option is (c)

18. The lowest allowed energy is eual to zero for

(a) the hydrogen atom

(b) a rigid rotor

(d) a particle in a 3-dimensional box

Ans. (b)

Sol. Lowest energy equal to zero for a rigid rotor

E = BJ (J + 1) J = 0,1,23 ....

J = 0

E = B × 0 (0 + 1)

E = 0

Correct option is (b)

19. According to the Debye-Hückel limiting law, if the concentration of a dilute aqueous solution of KCl is increased 4-fold, the value of in ( is the molal mean ionic activity coefficient) will

(a) decease by a factor of 2

(b) increase by a factor of 2

(d) increase by a factor of 4.

Ans. (a)

Sol.

Decrease by factor 2

Correct option is (a)

20. For the parallel first order reaction shown below

the value of k₁ is 1×10^–4 s^–1. If the reaction starts from X, the ratio of the concentrations of Y and Z at any given time during the course of the reaction is found to be The value of k₂ is:

(a) 1×10^–4s^–1

(b) 2.5×10^–5s^–1

(d) 4×10⁴s^–1

Ans. (c)

Sol.

K₁ = 10^–4 s^–1

21. The correct order of for the compounds in the IR spectrum is:

(a)

(b)

(c)

(d)

Ans. (c)

Sol.

electron density on metal decreases then M–C bond strength decreases

C–O bond strength increases

NMe₃ is stronger -donar

PX₃ are – donar as well as – acceptor

The – donating ability NMe₃ > PMe₃ > P(OPh)₃ > PCl₃

Hence, – Mo (CO)₃ PCl₃ > Mo(CO)₃ P(OPh₃) > Mo(CO)₃ (PMe₃)₃ > Mo(CO)₃ (NMe₃)₃

Correct option is (c)

22. 2.5 g of an iron compound upon suitable treatment yielded 0.391 g of iron (III) oxide. The percentage of iron in the compound is

(a) 10.94

(b) 12.15

(d) 9.11

Ans. (a)

Sol.

2 × 56 2 × 56 + 16 × 3

112 160

112 gm iron yield Fe₂O₃ = 160 gm

2.5 gm ion yield Fe₂O₃ = = 3.571

% of iron = 10.94

Correct option is (a)

23. In the reaction, , the compounds X and Y, respectively are

(a)

(b)

(c)

(d)

Ans. (b)

Sol.

24. The ¹H NMR spectrum of HD consists of a

(a) singlet

(b) 1:1 doublet

(d) 1:2:1 triplet.

Ans. (c)

Sol. HD ¹H NMR

Multiplicity = (2NI + 1) = (2 × 1 × 1 + 1) = 3 triplet

1 : 1 : 1

Correct option is (c)

25. The X-ray powder pattern of NaCl shows an intense cone at using X-rays of wave length 1.54×10^–8 cm. The spacing between the planes (in Å) of NaCl crystal is

(a) 1.41

(b) 2.82

(d) 5.63

Ans. (b)

Sol.

26. Among the following, the isoelectronic and isostructural pair is

(a) CO₂ and SO₂

(b) SO₃ and SeO₃

(c)

(d)

Ans. (b)

Sol.

27. Two samples have been given to you: A physical method that can be used to identify these compounds unambiguously is

(a) HPLC

(b) magnetic susceptibility

(d) Mössbauer spectroscopy

Ans. (b)

Sol. Here, [NiCl₂ (PPh₃)₂] will be paramagnetic, whereas [PdCl₂ (PPh₃)₂] will be diamagnetic. Thus, magnetic susceptibility can be used to identify these compounds unambigously.

Correct option is (b)

28. In the reaction , the conjugate acid-base pairs are

(a)

(b)

(c)

(d)

Ans. (a)

Sol.

29. Designate the following complexes X, Y and Z as inert or labile

X = [Al(C₂O₄)₃]^3– Y = [V(H₂O)₆]²⁺ Z = [Cr(C₂O₄)₃]^3–

(a) X and Y are inert; Z is labile

(b) X and Z are labile; Y is inert

(d) X is labile; Y and Z are inert

Ans. (d)

Sol. The complexes having d³ electronic configuration is most inert complexes.

Both are inner orbital complex, there is no low lying vacant d orbital. Hence only Y and Z are inert.

Correct option is (d)

30. In the reaction sequence:

X and Y, respectively, are

(a)

(b)

(c)

(d)

Ans. (b)

Sol.

31. The major product X (based on the preferred conformation) in the reaction

(a)

(b)

(c)

(d)

Ans. (b)

Sol.

32. In the reactions,

The major products X and Y, respectively are

(a)

(b)

(c)

(d)

Ans. (d)

Sol.

33. In the reaction

the major product X is

(a)

(b)

(c)

(d)

Ans. (c)

Sol.

34. Reaction of m-menthylanisole with lithium in liquid ammonia and t-butyl alcohol at –33°C generates compound X as the major product. Treatment of the compound X with dilute sulphuric acid produces compound Y as the major product. The compounds X and Y, respectively, are

(a)

(b)

(c)

(d)

Ans. (d)

Sol.

35. The number of signals that appear in the broad-band decoupled ¹³C NMR spectrum of ortho-, meta-and para-dichlorobenzenes, respectively, are

(a) 3, 4 and 2

(b) 3, 3 and 2

(d) 3, 4 and 4

Ans. (a)

Sol.

36. In the reaction sequence,

the structure of the major product Z and the overall yield for its formation from the ketone X, are

(a)

(b)

(c)

(d)

Ans. (b)

Sol.

Correct option is (b)

37. In the reaction sequence

the major product respectively, are:

(a)

(b)

(c)

(d)

Ans. (a)

Sol.

38. In the reaction sequence the major products X and Y, respectively are

(a)

(b)

(c)

(d)

Ans. (c)

Sol.

39.

39. In the reaction sequence

The major products X and Y, respectively are

(a)

(b)

(c)

(d)

Ans. (b)

Sol.

40. In the photochemical reaction

formation of the compound X can be inferred by the disappearance of the ¹H NMR signal at ¹H NMR spectrum of the starting material:

(a)

(b)

(c)

(d)

Ans. (a)

Sol.

The signal of –CHO proton disappear at 9.7 ppm

Correct option is (a)

41. The half-life (t_1/2) for the hydrolysis of an ester varies with the initial concentration of the reactant ([E]₀) as follows:

[E]₀/10^–2 mol L^–1 5.0 4.0 3.0

T_1/2 /s 240 300 400

The order of the reaction is:

(a) 0

(b) 1

(d) 3

Ans. (c)

Sol.

n = 2 Order of reaction is 2

Correct option is (c)

42. The fluorescene lifetime of a molecule in solution is 10 ns. If the flurosence quantum yield is 0.1, the rate constant of fluroscene decay is:

(a) 1×10⁹ s^–1 .

(b) 1×10⁸s^–1

(d) 9×10⁷ s^–1

Ans. (c)

Sol.

Correct option is (c)

43. The fundamental vibrational wavenumbers for H₂ and I₂ are 4403.2 cm^–1 and 214.5 cm^–1, respectively. The relative population of the first excited vibrational states of these two molecules compared to their respective ground states at 300 K are respectively.

(a) 6.75 ×10^–1 and 3.57 × 10^–1

(b) 6.75 × 10^–1and 3.57 and 3.57×10^–1

(d) 3.57×10^–1 and 6.75 × 10^–1

Ans. (b)

Sol.

44. The degeneracy of a quantum particle in a cubic box having energy four times that of the lowest energy is

(a) 3

(b) 6

(d) 4

Ans. (c)

Sol. 12h²/8ml² ——————————— (222)

11h²/8ml² ——————————— n = (311) (131) (113)

9h²/8ml² ——————————— n = (221) (122) (212)

6h²/8ml² ——————————— n = (211) (121) (112)

3h²/8ml² ——————————— n_x = 1, n_y = 1, n₂ = 1

45. The rotational Raman spectrum of ¹⁹F₂ shows a series of Stokes lines at 19230. 769 cm^–1 , 19227.238cm^–1 and 19223.707 cm^–1. The rotational constant for ¹⁹F₂ in GHz is:

(a) 26.484

(b) 52.968

(d) 3.531

Ans. (a)

Sol.

4B = 19230.769 – 19227.238

4B = 3.531

B = 88275 cm^–1

B = 0.88275 cm^–1 × c = 0.88275 × cm^–1 × 3 × 10¹⁰ cm/sec

B = 26.484 × 10⁹ Hz = 26.484 GHz

46. The de-Broglie wavelength for a He atom travelling at 1000 ms^–1 (typical speed at room temperature) is

(a) 99.7×10^–12m

(b) 199.4×10^–12m

(d) 99×10^–6m

Ans. (a)

Sol.

47. Given that the standard molar enthapies of formation of NO(g) and NO₂ (g) are, respectively, 90.3 kJ mol^–1 and 33.2 kJ mol^–1, the enthalpy change for the reaction 2NO(g) + O₂ (g) (g) 2NP₂ (g) is

(a) 16.6 kJ

(b) –57.1 kJ

(d) 57.1 kJ

Ans. (c)

Sol. 2NO(g) + O₂ (g) 2NO₂ (g)

Correct option is (c)

48. Among the following, the equilibrium which is NOT affected by an increase in pressure is

(a)

(b)

(c)

(d)

Ans. (d)

Sol. When = 0 then pressure has no effect on equilibrium.

In option (d); = 4 – 4 = 0

Correct option is (d)

49. The free energy changeof 1 mole of an ideal gas that is compressed isothermally from 1 atm to 2 atm is:

(a) RTln2

(b) –2RT

(d) 2RT

Ans. (a)

Sol.

50. Two liquids B and C form an ideal solution. In the figure below, the vapour pressure P of this solution is shown as a function of the mole fraction X_B, of component B.

Given a state of this vapour-liquid mixture whose overall composition corresponds to point E in the figure, the mole fractino of B in the vapour phase is approximately.

(a) 0.25

(b) 0.53.

(d) 0.80

Ans. (a)

Sol.

Common data for Q. 51 and Q. 52:

Treatment of W(CO)₆ with 1 equivalent of Na(C₅H₅) in THF solution gives the ionic compound M. Reaction of M with glacial acetic acid results in product N. The ¹H NMR spectrum of N displays two singlets of relative intensity 5:1. When N is heated, hydrogen gas is evolved and O is produced; O may also be prepared by refulxing W(CO)₆ with cyclopentadiene and H₂ is also produced. Treatment of O with an equivalent of Br₂ produces P. (Use the 18 electron rule as your guide).

51. The compounds M and N, respectively, are

(a)

(b)

(c)

(d)

Ans. (a)

Sol.

Correct option is (a)

52. The compounds O and P, respectively, are

(a)

(b)

(c)

(d)

Ans. (a)

Sol.

Correct option is (a)

Common data for Q. 53 and Q. 54.

An organic compound X(C₉H₁₀O) exhibited the following spectral data.

IR : 1680 cm^–1

¹H NMR : (2H, d, J 7.5 Hz), 7.2 (2H, d, J = 7.5 Hz), 2.7 (3H, s) and 2.4 (3H, s) compound X on treatment with m-chloroperbenzoic acid produced two isomeric compounds Y (major) and Z (minor)