B.Sc. 3rd Part Chemistry Question Bank BRABU
Here you can find the B.Sc. 3rd Part Chemisrty Honours Question Paper-V, Paper-VI and Paper-VII of Babasaheb Bhimrao Ambedkar Bihar University (BRABU) Muzaffarpur.
Exam-2020
CHEMISTRY (Hons.) Paper – VI
Answer any five questions.
Full Marks: 100
Time: 3hours
1. (a) Give a comparative account of valence bond and molecular orbital theory.
(b) Describe valence bond wave functions of H2 molecule.
2. (a) Find out the energy values associated with t2g and eg orbitals for octahedra complexes.
(b) Calculate the CFSE for paramagnetic [CoF and diamagnetic [Co (NH2)]+3 ions.
3. Give the reasons for the following:
(a) d-orbitals split in Octahedra field in opposite manner and to a different extent in comparison to tetrahedral field.
(b) Tetrahedral complexes are intensely coloured in comparison to octahedral complexes.
4. (a) Explain orbital contribution to magnetic moment and its quenching.
(b) Discuss ferromagnetic, anti ferromagnetic and ferrimagnetic behaviour of substances.
5. Explain any three of the following:
(a) Neutron activation analysis
(b) Moderators
(c) Liquid drop model
(d) Artificial radioactivity
6. (a) What are hard and soft acids and bases?
(b) Explain the acid-base strenth of hard and soft acids and bases.
7. Give an introductory idea about any two of the following:
(a) Gas chromatography
(b) Flame photometry
(c) Coulometry
8. (a) Discuss selection rules for electronic transitions.
(b) Draw orgel diagram of d² and d³ systems and predict possible electronic transitions.
9. Explain the following:
(a) Estimation of Ca++ ion by EDTA using complexometric titrations.
(b) How are inorganic polymers classified ? Give an example including structure of a:
(i) Straight chain
(ii) Trimeric and tetrameric cyclic sillicones.
B.Sc. 3rd Part Paper VI Exam- 2020
BRABU MuzaffarpurExam-2020
CHEMISTRY (Hons.) Paper – VI
Answer any five questions.
Full Marks: 100
Time: 3hours
1. (a) Give a comparative account of valence bond and molecular orbital theory.
(b) Describe valence bond wave functions of H2 molecule.
2. (a) Find out the energy values associated with t2g and eg orbitals for octahedra complexes.
(b) Calculate the CFSE for paramagnetic [CoF and diamagnetic [Co (NH2)]+3 ions.
3. Give the reasons for the following:
(a) d-orbitals split in Octahedra field in opposite manner and to a different extent in comparison to tetrahedral field.
(b) Tetrahedral complexes are intensely coloured in comparison to octahedral complexes.
4. (a) Explain orbital contribution to magnetic moment and its quenching.
(b) Discuss ferromagnetic, anti ferromagnetic and ferrimagnetic behaviour of substances.
5. Explain any three of the following:
(a) Neutron activation analysis
(b) Moderators
(c) Liquid drop model
(d) Artificial radioactivity
6. (a) What are hard and soft acids and bases?
(b) Explain the acid-base strenth of hard and soft acids and bases.
7. Give an introductory idea about any two of the following:
(a) Gas chromatography
(b) Flame photometry
(c) Coulometry
8. (a) Discuss selection rules for electronic transitions.
(b) Draw orgel diagram of d² and d³ systems and predict possible electronic transitions.
9. Explain the following:
(a) Estimation of Ca++ ion by EDTA using complexometric titrations.
(b) How are inorganic polymers classified ? Give an example including structure of a:
(i) Straight chain
(ii) Trimeric and tetrameric cyclic sillicones.
B.Sc. 3rd Part Paper VI Exam- 2019
BRABU MuzaffarpurExam-2019
CHEMISTRY (Hons.) Paper – VI
Answer any five questions.
Full Marks: 100
Time: 3hours
1. (a) Discuss valence bond theory of bonding is reference to formation of hydrohen molecule.
(b) Which one of the following pair has smaller bond length.
(i) N2+ and N2
(ii) O2− and O2
justify your answer on the basis of MOT.
(c) Show the overlap of the following atomic orbital along Z-axis.
(i) pz-pz
(i) py-py
(i) py-pz
2. (a) What do you mean by quenching of orbital angular momentum.
(b) Find out the free ion ground term of the following-
(i) d2 system
(i) d2 system
(c) Give the states obtained by LS coupling of the free ion ground term 5D. State the lowest energy state.
3. (a) How the d-orbitals splits in the octahedral crystal field.
(b) Which among the following has highest crystal field energy and why ?
(i) [FeF6]−3
(ii) [Fe(H2)6]+2
(iii) [FRh(H2)6]+3
(c) Calculate CFSE of the following-
(i) d4 (oh) low spin
(ii) d5 (td) high spin
4. (a) Explain the following (any one)
(i) Liquid drop model
(ii) Nuclear fussion reaction
(b) Fill up the blank-
(i) 92U235 + 0n1 → ... + 36Kr92 + 3 0n1
(ii) 7N14 + 0n1 → ... + 1H1
(c) Calculate the binding energy per nuclear for 8O16 which has a mass of 15.9949 amu.
5. (a) Draw the orgel diagram for the following-
(i) [V(H2O)6]+3
(ii) [Cu(H2O)6]+2
(b) Draw splitting diagram of 5D term in weak tetrahedral crystal field.
(c) Explain the color of MnO4−
6. (a) Explain the HSAB (Hard-soft acid base) principle.
(b) Give reason
(i) LiI and CsI reacts with each other although both are ionic.
(ii) BF3 readily combines with F−
(iii) SCN− ligands coordinates with Co+2 ion through N atom but with Pd+2, it coordinates through sulphur atom.
(iv) Agl2− is stable but AgF2 is not.
7. Write notes on any two of the following-
(a) Flame photometry
(b) Boranes
(c) Phosphonitric halides
(d) Artificial radio activity
(e) Principles of gas chromatographic
8. (a) "The magnetic moment of copper accetate dehydrate was observed as 1.34 B.M at 27°C." Give reason.
(b) Calculate magnetic moment of f1 and f3 system. Why they are different.
(c) Explain curie temperature.
10. (a) Define stepwise and overall stability constant. Establish a relation between them.
(b) "[Cr(en)3]2+ is more stable than [Cr(NH3)6]+2". Why?
(c) Why p orbital split is square planar crystal field but not is octahedral crystal field.
B.Sc. 3rd Part Paper VI Exam- 2018
BRABU MuzaffarpurExam-2018
CHEMISTRY (Hons.) Paper – VI
Answer any five questions.
Full Marks: 100
Time: 3hours
1. (a) Discuss molecular orbital wave function for H2, and H2+ ion.
(b) Give a quantitative description of sp and sp2 hybrid orbitals.
2. (a) Discuss the different source of paramagnetism and its temperature dependence.
(b) What is paramagnetic susceptibility ? Describe one method for its determination.
(c) Observed value of magnetic moment for Co+2 is higher than that of calculated by the spin only formula.
3. (a) Discuss the hybridization of atomic orbitals of central metal ion or atom and thereby suggest the geometry and magnetic moment (μs) of the following complex species-
[FeF6]−3, [Co(NH3)6]+3, [Ni(CO)4] and [Cucl4]
(b) With the help of crystal field theory explain the following-
(i) CuSO45H2O is blue.
(ii) K4FeF6 is high spin but K4Fe(CN)6 is low spin complex.
4. What are the defects of Valance bond theory as applied to complexes ? How has crystal field theory been able to overcome these defects ?
5. (a) Explain the splitting of d-orbitals in octahedral field of ligand in crystal field theory.
(b) Show by calculation that the lowering of stabilized orbitals is 0.4A, while the raising of the destabilised orbitals is 0.6A in an octahedral field.
(c) Discuss the factors on which the magnitude of Δ depends.
6. Write notes on-
(1) Chelates effect
(ii) Entropy effect
(iii) Spectrochemical series
(iv) Method of determination of stability constant.
7. (a) Explain why there is release of energy in both nuclear fission and nuclear fusion ?
(c) Show that neutron/proton ratio is an important clue in predicting nuclear stability.
(d) Explain the following-
(i) Moderator
(ii) Isotope dilution method
8. (a) Draw the orgel diagram for d4 system in octahedral and tetrahedral fields.
(b) Derive the ground term for d7 and d9 systems.
(c) Discuss selection rule for d-d transitions.
9. (a) Explain why position of F and CN in spectrochemical series differ ?
(b) Had permanent hardness of water is determined volumentrically using EDTA.
(c) Explain principle of TLC? How Rf factor is calculated ?
B.Sc. 3rd Part Paper VI Exam- 2017
BRABU MuzaffarpurExam-2017
CHEMISTRY (Hons.) Paper – VI
Answer any five questions.
Full Marks: 100
Time: 3hours
1. (a) Draw the energy versus internuclear distance plot for H2 molecule.
(b) Describe valence bond wave functions of H2 molecule.
2. (a) Give a comparative account of Valence Bond and Molecular Orbital Theory.
(b) Show that μs and μS+L values are different for Fe(II) but same of Fe(III).
(c) Discuss bonding in B2H6 molecule.
3. (a) Explain antiferromagnetism and ferromagnetism by Neel, Curie temperature and magnetic susceptibility graph.
(b) Explain magnetic susceptibility and magnetic moment.
(c) [v (H2O)6]+3 has lower than 2.83 BM; although there is orbital contribution. Explain.
4. (a) Describing the shapes of various d-orbitals, explain their splitting in tetrahedral field of ligands.
(b) For the same metal ligand set find out the relationship between Δo and Δt.
(c) With the help of crystal theory explain NiCl2.6H2O is green.
5. (a) Discuss the variation in ionic radii of M+2 ions of 3d-series.
(b) Explain thermodynamic stability of transition metal complexes.
(c) Define labile and inert complexes with suitable examples.
6. Write notes on the following-
(a) Nuclear stability
(b) Nuclear Binding Energy
(c) Artificial Radioactivity
(d) Liquid Drop Model
7. (a) On the basis of stability trend of complexes (Ahrland, Chatt and Davies) classify the metal ions and ligands.
(b) Explain intrinsic strength of acids, bases and HSAB concept with suitable example.
(c) Explain "Symbosis".
8. (a) Draw the Orgel diagram for d1 and d7 configuration in octahedral and tetrahedral field.
(b) Discuss the visible spectra of [Ti(H2O)6]+3 ion.
Derive the ground term for d4 and d5 systems.
9. Explain the following
(a) Estimation of Ca+2 and Mg+2 ion in a mixture by EDTA using complexometric titrations.
(b) How are inorganic polymers classified ? Give an example including structure of a (i) straight chain, (ii) Trimeric and tetrameric cyclic sillicones.
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