Chemistry(Ph.D.) 2017

Chemistry(Ph.D.)    (1077)

1.                    Among the following ions which one has the highest paramagnetism?

(A)[Zn(H₂O)₆]²⁺                                                          (B) [Cu(H₂O)₆]²⁺ 

(C) [Fe(H₂O)₆]²⁺                                                          (D) [Cr(H₂O)₆]³⁺     

2.                    In [NiF₆]^4-,  [FeF₆]^3- , [TiF₆]^2- and [CrF₂]

(A)    All shows JahnTaller distortion                 

(B)    (B) [NiF₆]^4- and [TiF₆]^2- shows JahnTaller distortion

(C)    Only [CrF₂] shows JahnTaller distortion 

(D)None of the above

3.                    Which of the following complex ions shows minimum intensity of absorption in UVVisible region?

(A)    [Cr(H₂O)₆]²⁺                                                         (B) [Mn(H₂O)₆]²⁺

            (C) [V(H2O)6]2+                                                                             (D) [Co(H2O)6]2+

4.                    The ESR spectrum of naphthalene radical anion consists of:

(A)    15 lines                 (B) 25 lines                              (C) 30 lines                  (D) 40 lines

5.                    The g value for the benzene radical anion is 2.0025. At what field would you search for resonance in a spectrometer operation at 9.302 GHz?

(A)    0.432 T                 (B) 0.332 T                              (C) 0.872 T                  (D) 0.243 T 

6.                    Melting point of NaCl, NaBr, NaI and NaF will be in order:

(A)    NaCl < NaI < NaF < NaBr                                  (B) NaBr < NaF < NaCl < NaI

            (C) NaI < NaBr < NaCl < NaF                                   (D) NaF < NaCl < NaBr < NaI

7.                    Which is maximum hydrated?

(A)    SiCl₄                     (B) AlCl₃                                            (C) MgCl₂                   (D) NaCl

8.                    Of the following mixtures of two pure acids the strongest acid will be:

(A)    HNO₃ + H₂SO₄                                                    (B) H₃BO₃ + H₂SO₄

            (C) HClO₄ + H₂SO₄                                        (D) KHSO₄ + H₂SO₄

9.                    CO₂ cannot be obtained by heating:

(A)    Na₂CO₃  (B) Li₂CO₃   (C) CaCO₃  (D) Ca(HCO₃)₂

10.                Solution of Na metal in liquid NH₃, is a strong reductant due to the presence of:

(A)    Sodium ion                                                          (B) Solvated electrons

            (C) Sodium amide                                                       (D) Sodium hydride

11.                B H B bridge in B₂H₆ is formed by sharing of: 

(A)    2 electrons (B) 4 electrons (C) 1 electrons (D) 3 electrons

12.                PI₃ upon hydrolysis gives:

(A)    Monobasic acid and dibasic acid   (B) Monobasic acid and tribasic acid

(C) Monobasic acid and a salt                                    (D) Dibasic acid and tribasic acid

13.                Which one of the following is sp3d hybridised:

(A)    XeO₃                    (B) XeOF₂                                         (C) XeOF₄                   (D) XeF₄

14.                The square pyramidal molecular shape is adopted by:

(A)    SOF₄                    (B) PF₅                                                (C) XeOF₄                   (D) ScOCl₄

15.                From molecular orbital configuration of CO and NO+, we would predict:

(A)    Both have a bond order of 3

(B)    Both are paramagnetic

(C)    Both will readily loss an electron to form CO⁺ or NO²⁺

(D)    Both CO and NO+ should not exist

16.                Indicate the organometallic complex that obeys the EAN rule:

(A)    Ni(π-C₅H₅)₂                                                         (B) (C₂H₅)W(CO)₂(π-C₅H₅)

            (C) Co(C₆H₆)                                                  (D) (π-C₅H₅)₂TiCl₂

17.                The trivalent ion having largest size is:

(A)    La                         (B) Ti                          (C) Zr                          (D) Hf

18.                The absolute configuration of two chiral centers (C-1, C-6) present in compound given below is:

O

O

                                                ^H         

(A)    1R, 6R                 (B) 1R, 6S                               (C) 1S, 6R                   (D) 1S, 6S

19.                The relation between compound X and Y is:

HCH 3    CH

CH3       H          CH3

                        X          Y         

(A)    Achiral identical mirror image                             (B) Enantiomers

(C) Meso structure                                                      (D) Racemic mixture

20.                Singlet and triplet carbene can be identified by reaction with:          

(A)    Alkene  (B) Electrophile  (C) cis or trans Alkene   (D) Benzyne

21.                The relationship between two compounds given below are:

O         O

           

                                    H             H            

(A)    Enantiomers                                                         (B) Diastereomers

            (C) Meso                                                                     (D) Regioisomers

22.                Which of the following compound is aromatic in nature?

    A     B    C  D

23.                Alkyl halide with halogen at bridge head are inert to nucleophilic substitution through S_N1 mechanism is due to 

(A)    Steric strain           

(B)    Poor leaving ability of halogen at bridge head

(C)    Rigid geometry  

(D)    Formation of carbocation at bridge head is not possible

24.                Which rule prevent the formation of double bond at bridge head?

(A)    Bredts rule                                                           (B) Crams rule

            (C) Hofmann rule                                                        (D) Saytzeff Rule

25.                The major product formed in the following reaction sequence is:

CH₃

*    

O-CH₂CH=CH₂ 200 °C

             CH3           

CH3                     CH₃

OHOH

(A)( B )

CH₃CH₃

CH CH=CH₂ CH₂CH=CH₂

*   *

CH₃

OH            (D) OH

(C)

*   H2C=HCH2CCH3       H₂C=HCH₂*CCH₃

26.                The selective reduction of α,β-unsaturated ketones to α,β-unsaturated alcohols can be achieved by:

(A)    NaBH₄                                                                 (B) BH₃. SMe₂             

            (C)  LiAlH₄                                                                 (D)   NaBH₄ / CeCl₃

27.                The most suitable reagent for carry out the transformation given below:

OH              O

OH

                 

(A)    Jones reagent                                                       (B) Manganese dioxide            

(C)  Lead tetraacetate                                                 (D)   Swarn’s reagent

28.                The most suitable reagent for carry out the transformation given below:

OH

CHO

                                    ^O        

(A)    NaBH₄                                                                 (B) BH₃. SMe₂             

            (C)  LiAlH₄                                                                 (D)   DIBAL-H

29.                Cope rearrangement is an example of:

(A)    [2,3] Sigmatropic shift                (B) [2,4] Sigmatropic shift   (C)  [3,3] Sigmatropic shift    (D) [1,3] Sigmatropic shift

30.                The following reaction is an example of:

Heat

SO₂ S

                        O2          

(A)    Electrocyclic reaction                 (B) Anti cycloaddition reaction (C)Sigmatropic rearrangement   (D)   Cheleotropic reaction

31.                tert.-Butoxycarbonyl group i.e (CH₃)₃COCO-) protected amine can be deprotected by:

(A)    10%  KOH solution                                             (B) CF₃COOH

            (C) Lithium aluminum hydride                                   (D) Diboran

32.                Aldehydes can be protected as acetals by reaction of aldehydes with excess of alcohol in presence of:    

(A)    10%  KOH solution                                             (B) 10% HCl

            (C) HCl gas                                                                 (D) 10 % H2SO₄

33.                Predict the structure of compound with molecular formula C₈H₁₆. ¹H NMR of this compound exhibit only one signal at δ (1.29, 16H). The compound is:

(A)    Cycloctane                                                           (B) Methyl cyloheptane

            (C) 1,2-Dimethyl cyclohexane                                    (D) 1,2,3-Trimethyl cyclopentane

34.                In the mass spectrum of 1, 2-dibromoethane, approximate ratio of peaks at m/z values 186(M⁺), 188(M⁺+2), 190 (M⁺+4) will be: 

(A)    6:1:4                    (B) 9:6:1                                 (C) 1:2:1                     (D) 4:2:3          

35.                X-rays with wavelength 1.54 Å are reflected from the (1 1 0) planes of a cubic crystal with unit cell a = 6 Å. The Bragg angel, θ, for first order of reflection i.e. n = 1 would be

(A)    10.46^o                   (B) 21.30^o                                (C) 33.01^o                    (D) 46.59^o

36.                A first order reaction is found to have a rate constant, k = 5.5 x 10^-14 sec^-1. The half-life of the reaction is: 

(A)    1.81 x 10¹⁴ sec                                                     (B) 1.26 x 10¹³ sec 

(C) 1.81 x 10¹³ sec                                                      (D) 1.26 x 10¹⁴ sec

37.                Variation of chemical potential with pressure results

(A)    Partial molar entropy                                           (B) Partial molar volume

(C) Partial molar enthalpy                                           (D) Partial molar internal energy

38.                The heat of reaction ½ H₂ + ½ Cl₂  →  HCl at 27⁰C is –22.1 kcal. Calculate the heat of reaction at 77⁰C. The molar heat capacities at constant pressure at 27⁰C for hydrogen, chlorine and HCl are 6.82, 7.70 and 6.80 cal mol^-1 respectively.

(A)    -27.832 kcal                                                         (B) -26.231 kcal

(C) -22.123 kcal                                                          (D) -21.978 kcal

39.                Activity coefficients calculated using Debye-Huckel law are always

(A)    Less than zero                                                      (B) Equal to one 

(C) Less than one                                                        (D) Greater than one

40.                If the wave function of a particle trapped in space between x = 0 and x = L is given by  Ψ(x) = Asin(2Πx/L), where A is a constant. For which value(s) of x will the probability of the finding of particle be maximum

(A)    L/2                                                                      (B) L/4

(C) L/6 and L/3                                                           (D) L/4 and3L/4           

41.                The protecting power of lyophilic colloidal sol is expressed in terms of

(A)    Critical micelle concentration                              (B) Oxidation number

(C) Coagulation value                                                 (D) Gold number

42.                Which of the following methods gives the number average molecular weight of a polymer?

(A)    Light scattering method                          (B) Viscosity method

                        (C)  Sedimentation equilibrium method                     (D) Sedimentation velocity method 

43.                SiF₄, BF₄^- belongs to which point group?

(A)    O_h                         (B) T_d                                  (C) C_2v, D_2h                 (D) D_2h, C_2v

44.                The function of alum used for purification of water is to 

(A)    Coagulate the sol particles                                   (B) Disperse the sol particles               

(C) Emulsify  the sol particles                                     (D) Absorb the sol particles

             

45.                If we operate a Carnot’s engine between the freezing point and boiling point of water, what will be the efficiency of that engine?

(A)    100 %                   (B) 0 %                                    (C) 27 %                      (D) 73%

(5)

46.                If the molar conductance at infinite dilution of NaCl, HCl and CH₃COONa are 126.4, 425.9 and 91.0 S cm² mol^-1 respectively. The molar conductance at infinite dilution for Acetic acid is:  

(A)    390.5 S cm² mol^-1                                                 (B) 300.9 S cm² mol^-1  

(C) 290.5 S cm² mol^-1                                                  (D) 200.9 S cm² mol^-1  

47.                The Tafel equation is an equation in electrochemical kinetics relating 

(A)    The rate of an electrochemical reaction to the concentration

(B)    Cell potential to concentration

(C)    The rate of diffusion current to the potential                                                       

(D)    The rate of an electrochemical reaction to the overpotential

48.                The pure rotational spectrum of CO consists of a series of equally spaced lines separated by 3.84235 cm^-1. The atomic masses are: ¹²C = 19.92168 x 10^-27 kg and ¹⁶O = 26.56136 x 10^-27 kg. The internuclear distance of the molecule is

(A)    2.312 Å                (B) 1.456 Å                             (C) 1.131 Å                 (D) 1.921 Å

49.                What is the equilibrium constant for the reaction given below at 298 K, if E_cell = 1.10 V at 298 K?

                        Zn²⁺ (aq) + Cu (s)         Zn(s) + Cu^{2+ (}aq)

(A)    e57.8                             (B) 1057.8                                           (C) 1085.7                     (D) e85.7

50.                In a solid “AB’ having the NaCl structure, “A” atoms occupy the corners of the cubic unit cell. If all the face centered atoms along one of the axes are removed, then the resultant stoichiometry of the solid is:

(A)    AB₂                      (B) A₃B₄                                             (C) A₄B₃                      (D) A₂B