QUESTION PAPER CHEMISTRY-CY

Size: px

Start display at page:

Download "QUESTION PAPER CHEMISTRY-CY"

Jade McKinney
5 years ago
Views:

1 Q.1 Q.5 : Carry E mark each. QUESTI AER CEMISTRY-CY 1. The Lewis acidity of B 3 is less than B 3 even though fluorine is more electronegative than chlorine. It is due to stronger p(b)-p() -bonding stronger p(b)-p() -bonding stronger p(b)-p() -bonding stronger p(b)-p() -bonding. yrozenes are a class of silicate minerals, which exhibit a polymeric chain structure, as shown below 1 Its simplest repeat unit is = Silicon = xygen Si 4 4 Si 3 Si 6 7 Si Among the following pentachlorides the one which does not exist due to the inertpair effect is 5 Bi 5 Sb 5 As 5 4. B theory predicts that magnesium is an insulator. owever, in practice it acts as a conductor due to presence of filled 3s orbital overlap of filled p filled 3s orbital overlap of filled 3s emtpy 3p orbital presence of unfilled 3p orbital 5. The number of framework electron pairs present in the borane cluster [B 1 1 ] is: The reaction between {d 4 ] C 4 produces a new compound. Compare to free C 4, the C C bond order of the product is: between 1 less than 1 unaltered greater than 7. Among the following pair of metal ions present in ature, the first one functions as an electrontransfer agent the second one catalyzes the hydrolysis reactions. The correct pair is e Zn Mg e Co Mo Ca Cu 8. Structurally nickellocene is similar to ferrocene. ickellocene attains stability due to the formation of a monocation a dication a monoanion a dianion 9. The absolute configurations for compounds X Y, respectively are Et Br Y X R, S S, R R, R S, S

2 QUESTI AER 10. In the reaction, C 3 S a 180ºC the major product is C 3 C 3 C Among the following, a pair of resolvable configurational enantiomers is given by cis-1, -dimethylcyclohexane cis-1, 3-dimethylcyclohexane cis-1, 4-dimethylcyclohexane trans-1, 3-dimethylcyclohexane 1. In the reaction, the major product is: C 13. The decreasing order of isoelectric point for the following amino acids is Lysine Alanine Glutamic acid (I) (II) (III) I > II > III II > I > III III > I > II I > III > II 14. The decreasing order of the reactivity of the following compounds towards electrophiles is S I II III II > I > III II > III > I III > I > II I > II > III 15. In the reaction, heat

3 the major product is QUESTI AER The decreasing order of acidity of marked of the following molecules is (I) (II) (III) I > II > III III > I > II III > II > I II > I > III 17. The decreasing order of nucleophilicity for the following anions is C3C, C3, C65, 3 C3C C3 C65 3 C3 3 C65 C3C C3 C65 C3C 3 C65 C3 3 C3C 18. The molar entropy of crystallline C at absolute zero is Zero Rln Rln Rln 19. or an ideal gas T V T V V T 0 T V T V V T 1 T V T V V T 1 T V T V V T 0. Among W (work), Q (heat), U(internal energy) S(entropy) W U are path functions but Q S are state functions. W S are path functions but Q U are state functions. S U are path functions but Q W are state functions. W Q are path functions but U S are state functions. 1 x 1. or eigen functions 1 sin b b x sin of particle in a 1-D box of length b b b 0 x b 1 is normalized but not orthogonal to 1 is normalized but not orthogonal to is normalized orthogonal to 1 is neither normalized nor orthogonal to 1. The bond order of C molecule is 0 1 3

4 QUESTI AER 3. Sulfur can exist in four phases. The possible number of triple points is The stard reduction potentials at 98K for single electrodes are given below: Electrode Electrode otential (volt) Mg + /Mg.34 Zn + /Zn 0.76 e + /e 0.44 rom this we can infer that Zn can reduce both Mg + e + e can reduce both Mg + Zn + Mg can reduce both Zn + e + Mg can reduce Zn + but not e or the pair of reactions given below (i) g 3 g g 3 4 (ii) 1 g 3 g 3 g If at a particular temperature, K 1 K are the equilibrium constants for reactions (i) (ii) respectively, then K1 K K K K K K 1 Q.6 Q.55 : Carry TW marks each. 6. According to VSER model, the shape of [Xe 5 ] is ctahedral Trigonal bipyramidal square pyramidal pentagonal monopyramidal 7. The number of unpaired electron(s) present in the species [e( ) 5 ()] + which is formed during brown ring test is: e 3 4 Co 3 4 are metal oxides having spinel structure. Considering their CSEs, the correct statment regarding their structure is both have normal spinel structure both have inverse spinel structure e 3 4 has normal Co 3 4 has inverse spinel structure e 3 4 has inverse Co 3 4 has normal spinel structure. 9. The mechanism of the reaction between [e(c) 6 ] 4 [e(bpy) 3 ] 3+ (bpy =, bipyridine) is outer-sphere electron-transfer inner-sphere electron-transfer self-exchange reaction lig-exchange followed by electron transfer. 30. The d-d absorption b of [e( ) 6 ] + is split due to presence of octahedral geometry static Jahn-Teller distortion dynamic Jahn-Teller distortion presence of trigonal bipyramidal geometry. 31. The crystal-field symbol for the ground-state of [Mn(C) 6 ] 4 is T g 1 A 1g 5 E g 6 A1g 1 1 K

5 3. In the following reactions: QUESTI AER 5 X C 3 C Y CC the reagent/conditions X Y are X = B 3 ; Y = heating at 150ºC X = a; Y = heating at 5ºC X = 4 ; Y = X = C 3 S 3 ; Y = S 4 I n 33. [Co 4 ] is a blue coloured complex. Controlled-treatment of this complex with water generates two isomeric light pink coloure complexes of composition [Co( ) 4 ]. Identify the correct point groups for [Co 4 ] two isomeric complexes [Co( ) 4 ]. D h (C v C h ) T d (C v D 4h ) D 4h (C v D 4h ) T d (C v C 4v ) 34. In the reaction Et C C (i) B 6 (ii) + the major product is: 35. In the reaction, (i) heat (ii) S 4 the major product is: 36. In the following reaction sequence (i) /y (ii) light (iii) hydrolysis

6 the major product is C C QUESTI AER C C In the reaction, [Y] 3 the major products, [Y], respectively, are mcba C C C C 38. In the reaction, C C Sn 4 the major product is 39. In the reaction sequence C (i) g(ac) / (ii) ab 4 (C 3 ) C [Y] the major products, [Y] respectively, are

7 QUESTI AER The change in entropy when two moles of Argon gas are heated at constant volume from 300K to 500K is: 1.74 J K 1 mole J K 1 mole J K 1 mole J K 1 mole At any temperature T, the fugacity coefficient is given by Z 1 In d ' ' 0 where Z is the compressiblity factor. The fugacity coefficient of a real gas governed by equations of state, (V b) = RT with b a constant is given by RT RT b e b b b RT e RT 4. The specific rate constant of decomposition of a compound is represented by 1000 Ink 5.0 T The activation energy of decomposition for this compound at 300K is 4 kcal/mole 1 kcal/mole 4 cal/mole 1 cal/mole The commutator x, p x is equal to hx 3hx i i 44. An electron of mass m is confined to a one dimensional box of length b. If it makes a radiative transition from second excited state to the ground state, the frequency of the photon emitted is 9h 8mb 3h 8mb hx i h mb 3hx i h mb

8 QUESTI AER 45. The point group of CI 3 molecule its corresponding number of irreducible representation are respectively. C 3v 4 C v 4 C 3v 3 C v The most populated rotational state for (B = 8.5 cm 1 ) at 300 K is: The ratio of life times of two states that gives rise to line widths of 1.0 cm 1 0. cm 1 respectively is: 1 : 1 : 5 : 1 5 : 1 Commond Data Questions: Commond data for Q.48 Q.49: A six-coordinate transition-metal complex is ESR Mossbauer active. The effective magnetic moment of this complex is 5.9 B.M. 48. The metal-ion along with its oxidation state the number of unpaired electron present are e(ii) 4 Mn(II) 5 e(iii) 1 e(iii) The complex is [Mn( ) 6 ] + [e(c) 6 ] 3 [e( ) 6 ] + [e( ) 6 ] 3+ Common data for Q.50 Q.51: An organic compound (C ) exhibits the following spectral data IR: 170 cm 1 1 MR:.35 (s, 6), 3.30 (s, 3), 3.83 (t, ), 4.4 (t, ), 7.07 (s, 1), 7.58 (s, ) The compound with an excess of MgBr gives a 1 : 1 mixture of compounds [Y] [Z]. The compound [Z] exhibits the following 1 MR data:.0(bs, 1), 3.30 (s, 3), 3.56(t, ), 3.70 (t, ) 50. The compound is: The compound [Y[ is:

9 QUESTI AER Linked Answer Q.5 Q.53: In the reaction sequence C MgBr 3 C 3 + (major) + [Y] (minor) (i) Ts/y (ii) aet/et [Z] 5. The compound is: 9 C 3 3 C 3 C 3 C C 3 3 C C The compound [Z] is: Et Et Statement for Linked Answer Q.54 Q.55: In the m vs T diagram for different phases of the same substance at one atmospheric pressure, the lines A, B C compound to A C 3 B µ C E D T 54. Based on the above diagram. A represents the change in chemical potential as a function of temperature for the solid phase, B for the liquid C for the gas. A represents the change in chemical potential as a function of temperature for the gas phase, B for the gas C for the solid A represents the change in chemical potential as a function of temperaturefor the liquid phase, B for the gas C for the solid A represents the change in chemical potential as a function of temperaturefor the gas phase, B for the gas C for the liquid. 55. rom the same diagram D represents boiling point, E sublimation point melting point. E represents boiling point, D sublimation point melting point. E represents melting point, sublimation point D boiling point. D represents melting point, boiling point E sublimation point. ***** ED TE QUESTI AER *****

QUESTION PAPER CHEMISTRY-CY

QUESTION PAPER CHEMISTRY-CY Q.1 Q.5 : Carry E mark each. CEMISTRY-CY 1. Jahn-Teller distortion of CuS 4.5 acts to Raise symmetry Remove an electronic degeneracy Cause loss of ligand Promote a d-electron to an antibonding molecular