Q7/15L/11-14

Reg. No

St. Joseph’s College of Arts & Science (Autonomous) St. Joseph’s College Road, Cuddalore – 607001 PCH702S - INORGANIC CHEMISTRY - I

Time : 3 hrs

Max Marks :75 SECTION – A (20X1=20) Answer ALL Questions

I. Choose the best answer 1. Thortvetite, Sc2Si2O7 is a) A pyrosilicate c) A sheet silicate

b) An orthosilicate d) An amphibole

2. The volume (in mL) of 0.1 M AgNO3 required for complex precipitation of chloride ions present in 30 mL of 0.01 M solution of [Cr(H2O)5Cl]Cl2, as silver chloride is close to a) 4 b) 4 c) 5 d) 6 3. (Crystal Field Theory) Which one of the following statements is FALSE? a) In an octahedral crystal field, the d electrons on a metal ion occupy the eg set of orbitals before they occupy the t2g set of orbitals. b) Diamagnetic metal ions cannot have an odd number of electrons. c) Low spin complexes can be paramagnetic. d) In high spin octahedral complexes, oct is less than the electron pairing energy, and is relatively very small. e) Low spin complexes contain strong field ligands. 4. Which one of the following complexes can exhibit geometrical isomerism? a) [Pt(NH3)2Cl2] (square planar) b) [Zn(NH3)2Cl2] (tetrahedral) c) [Cu(NH3)4]2+ (square planar) 1

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d) [Co(NH3)5Cl]2+ (octahedral) (linear) e) [Cu(CN)2]5. Why are many coordination compounds colored? a) The equilibrium established between the coordination compounds and air lies on the product side. b) The energy required to excite an electron to an excited state is often the same as the energy of light in the visible region. c) The Crayola Corporation likes it that way. d) They all absorb water vapor, which normally hides all of colors. 6. Diaminopropane exhibit a) Coordinate isomerism c) Linkage isomerism

b) Lignad isomerism d) Optical isomerism

7. The coordination number of phosphorus in [PMo12O40]3- is a) 2 b) 4 c) 4 d) 6 8. In chelation reaction, Which type of ring is more stable ? a) 4 Membered ring b) 5 Membered ring c) 8 Membered ring d) 3Membered ring 9. Which of the following is a nido-borane? a) B4H10 b) B5H9 c) [B6H6]2-

d) B5H11

10. The species having metal-metal bond is: a)Mn2(CO)10 b)Al2(CH3)6 c)V2(O)12

d)Al2(OPri)12

II. Fill in the blanks 11. The number of Isomers exhibited by the octahedral Complex ion + [ Co(NH3 )4 F2 ] is -----------. 12. Corrin ring is present in _______ 13. In normal silicates, each silicon atom is surrounded by ------------- oxygen atoms in a ---------- geometry

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14. We would expect both FeF63- and Fe(CN)63- to form-----------structure. 15. The complex [ Zn(NH3 )2 Cl2 ] does not exhibit cis-trans isomerism. The geometry of this complex must be __________. 2+

III. Match the following 16. K+

Template effect

17. Crown ethers

18-C-6

18. Chelation

NH2-(CH2)n-NH2

19. Potentiometric method

Thermodynamic effect

20. Soccer ligand(2H+)

Stability constant Kinetic effect SECTION – B (10X2=20) Answer any TEN Questions

21. Give the spectrochemical series. 22. Calculate the styx number of B4 H10 23. Even though Cu+ and K+ have similar size and small charge,Cu+ forms more stable complex than K+ with a particular ligand .Explain. 24. Account : A phosphate solution gives yellow precipitate with an excess of Ammonium molybdate solution 25. How is it possible for nido -7,8[ C 2B 9 H11]2- to get involved in the synthesis of ferrocene analogue ? 3

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26. Describe the behaviour of a complex which is both thermodynamically stable and kinetically labile . 27. What are amphiboles? 28. Draw the structure of paratungstate. 29. Why [Ti(H2O6] 3+ is purple in colour ? 30. Differentiate corrins from porphyrins. 31. Writ a note on Schiff's base. 32. How many total isomers (structural isomers and stereoisomers) exist for the complex ion [Co(NH3)5Cl]2+? SECTION – C (5X7=35) Answer any FIVE Questions 33. a) Explain the structure of S4N4. (3) b) Account for the short Re-Re bond length and eclipsed (2+2) configuration of Re2 Cl 8 34. a) Distinguish between stepwise and overall formation constants and also derive the relationship between them. (2+3) b) Account for the following: c) Log β for [Ag(NH3)2]+ is 7.2 whereas log β for ) [Ag (en)]+ is 6.0 (2) 35. a) The styx number of a borane is 3003. Arrive at its structure.(2) b) Place each of the molecules or ions in the correct structural classes. (5) i) B 10 C2 H 12 ii)[B 11 CH 12] iii)[B12 H12 ]2iv)B 3 C 2 H7 v)[B 9 CH 10 ]36. a) Explain the optical isomerism in 6 coordinated complexes. b) Explain ORD &CD with an suitable example. 4

(3) (4)

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37. a) How will you determine the stability constant of complexes by potentiometric method. (3) b) Explain the role of thermodynamic and kinetic template effect in the formation of a complex. (4) 38. a) Explain the crystalfield splitting in square planar complexes.(4) b) Which of the following compounds would be paramagnetic and why? (3) a) Sc(NH3)63+ (high spin) b) Zn(OH)42- (tetrahedral) c) Co(NH3)63+ (high spin) d) Fe(CN)64- (low spin) 39. a) How will you convert orthocarborane into its meta and para isomer And explain the ‘dsd’ mechanism also. (2+2) b) Draw the structure of Fe 3 (CO) 12 and calculate the EAN of iron atom in Different positions. (3)

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