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#### All Chapter 5 Marks

12th Standard EM

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Chemistry

Time : 06:00:00 Hrs
Total Marks : 300
60 x 5 = 300
1. Explain the principle of electrolytic refining with an example.

2. The selection of reducing agent depends on the thermodynamic factor: Explain with an example.

3. Explain froth flotation, with diagram.

4. Explain concentration by magnetic separation with diagram.

5. Write a note on zeolites.

6. A double salt which contains fourth period alkali metal (A) on heating at 500K gives (B). aqueous solution of (B) gives white precipitate with BaCl2 and gives a red colour compound with alizarin. Identify A and B.

7. What are the various methods by which carbon-di-oxide is prepared?

8. Distinguish between diamond and graphite.

9. Suggest a reason why HF is a weak acid, whereas binary acids of the all other halogens are strong acids.

10. Complete the following reactions.
1. NaCl + MnO2 + H2SO4
2. NaNO2 + HCl ⟶
3. IO3-+ I- + H+ ⟶
4. I2 + S2O32- ⟶
5. P4 + NaOH + H2O ⟶
6. AgNO3 + PH3 ⟶
7. Mg + HNO3 ⟶
8. KCIO3 $\overset { a }{ \longrightarrow }$
9. $\quad Cu+\overset { Hotconc }{ { H }_{ 2 }SO_{ 4 } }$ ⟶
10. Sb + Cl2 ⟶
11. HBr + H2SO4 ⟶
12. XeF6 + H2O ⟶
13. XeO64- + Mn2+ + H+ ⟶
14. XeOF4 + SiO2 ⟶
15. $Xe+{ F }_{ 2 }\overset { Ni/200atm }{ \underset { 400^{ 0 }C }{ \longrightarrow } }$.

11. An amorphous solid (A) burns in air to form a gas (B)which turns lime water milky. The gas is also produced as a byproduct during roasting of sulphide ore. This gas decolourises acidified aqueous KMnO4 solution and reduces Fe3+ to Fe2+. Identify the solid 'A' and the gas 'B' and write the reactions involved.

12. Explain the oxidising property of sulphuric acid.

13. Why europium (II) is more stable than Cerium (II)?

14. predict which of the following will be coloured in aqueous solution Ti2+ , V3+ Sc4+, Cu+ ,Sc3+, Fe3+, Ni2+ and Co3+

15. Justify the following statement.
"Elements of the first transition series possess many properties different from those of heavier transition elements".

16. Write a short note on the oxidation states of 3d series elements.

17. What is crystal field stabilization energy (CFSE)?

18. On the basis of VB theory explain the nature of bonding in [CoC2O4)3]3-

19. Mention the type of hybridisation and magnetic property of the following complexes using VB theory a) [FeF6]4- b) [Fe(CN)6]4-

20. How are metal carbonyls classified based on the structure?

21. An atom crystallizes in fcc crystal lattice and has a density of 103 gcm−3 with unit cell edge length of 100pm. calculate the number of atoms present in 1 g of crystal.

22. Write a note on Frenkel defect.

23. Ionic solids, which have anionic vacancies due to metal excess defect, develop colour. Explain with the help of a suitable example.

24. Explain the following:
Similarities and differences between metallic and ionic crystals.

25. Benzene diazonium chloride in aqueous solution decomposes according to the quation ${ C }_{ 6 }{ H }_{ 5 }{ N }_{ 2 }Cl\longrightarrow { C }_{ 6 }{ H }_{ 5 }Cl+{ N }_{ 2 }$ Starting with an initial concentration of 101 g L-1, the volume of N2 gas obtained at 50 °C at different intervals of time was found to be as under:

 t(min) 6 12 18 24 30 $\infty$ Vol.of N2 (ml) 19.3 32.6 41.3 46.5 50.4 58.3

Show that the above reaction follows the first order kinetics. What is the value of the rate constant?

26. In a pseudo first order hydrolysis of ester in water, the following results were obtained.

1 0 30 60 90
[Ester]mol L-1 0.55 0.31 0.17 0.085

(i) Calculate the average rate of reaction between the time interval 30 to 60 seconds.
(i) Calculate the pseudo first order rate constant for the hydrolysis of ester.

27. For the reaction R - P, the concentration of a reactant changes from 0.03 M to 0.02 M in 25 minutes. Calculate the average rate of reaction using units of time both in minutes and second.

28. The rate constant of a reaction at 400 and 200K are 0.04 and 0.02 s-1 respectively. Calculate the value of activation energy

29. Will a precipitate be formed when 0.150 L of 0.1M Pb(NO3)2 and 0.100L of 0.2 M NaCl are mixed?$K_{sp}\quad(PbCl_{2})=1.2\times10^{-5}$.

30. Establish a relationship between the solubility product and molar solubility for the following
a) BaSO b)Ag2(CrO4)

31. Calculate the pH of 0.1 M acetic acid if its ionisation constant Ka = 1.8 X 10-5.

32. Derive the hydrolysis constant for the hydrolysis of salt of strong base and weak acid. Deduce its pH

33. For the cell Mg (s) Mg2+(aq)||Ag2+(aq)|Ag(s), calculate the equilibrium constant at 250C and maximum work that can be obtained during operation of cell. Given : $E^{0}_{Mg^{2+}|Mg}$=-237V and $E^{0}|_{Ag^{2+}|Ag}$=0.80V.

34. Ionic conductance at infinite dilution of Al3+ and SO4 2- are 189 and 160 mho cm2 equiv-1. Calculate the equivalent and molar conductance of the electrolyte Al2 (SO4)3 at infinite dilution.

35. The equivalent conductances at infinite dilution of HCl, CH3COONa and NaCl are 42616, 91.0 and 126.45 ohm-1 cm2 gm equuivalent-1 respectively. Calculate the equivalent conductance (λ) of acetic acid

36. The emf of the half cell Cu2+(aq)/ Cu(s). containing 0.01 M Cu2+solution is + 0.301V Calculate the standard emf of the half cell

37. Explain any one method for coagulation

38. Explain intermediate compound formation theory of catalysis with an example

39. Write a note on phase transfer catalysis.

40. Explain the electrical property of colloids! with a neat diagram.

41. What will be the product for the following reaction acetylchloride $\\ \\ \overset { (i)CH_{ 3 }MgBr }{ \underset { (ii){ H }_{ 2 }{ O }^{ + } }{ \longrightarrow } } \times \overset { acid{ k }_{ 2 }{ cr }_{ 2 }{ o }_{ 7 } }{ \longrightarrow } A$ Identify X and A

42. Explain the mechanism involved in the intermolecular dehydration of alcohols to give ethers.

43. Distinguish between (a) Ethanol and phenol (b) Phenol and acetic acid (c) Phenol and aniline (d) Phenol and anisole.

44. An organic compound (A) of molecular formula C6H6O gives violet colour with neutral FeCI3. (A) gives maximum of two isomers (B) and (C) when an alkaline solution of (A) is refluxed with CCI4 (A) also reacts with C6H5N2CI to give the compound (D) which is red orange dye. Identify (A), (B), (C) and (D). Explain with suitable chemical reactions.

45. Write the structure of the major product of the aldol condensation of benzaldehyde with acetone.

46. Complete the following reaction
${ CH }_{ 3 }-{ CH }_{ 2 }-{ CH }_{ 2 }-\underset { \overset { || }{ O } }{ C } -{ CH }_{ 3 }\overset { HO-{ CH }_{ 2 }-{ CH }_{ 2 }-OH }{ \underset { { H }^{ + } }{ \longrightarrow } } ?$

47. An organic compound (A) C2H3OCI on treatment with Pd and BaSO4 gives (B) C2H4O which answers iodoform test. (B) when treated with cone. H2SO4 undergoes polymerisation to give (C) .a cyclic compound. Identify (A), (B) and (C) and explain the reactions.

48. Compound (A) with Molecular formula C7H6O does not reduce Fehling's solution. Compound (A) reacts with acetone in the presence of NaOH to give a compound (B) which is an α, β-unsa,turated compound. Further (A) reacts with dimethyl aniline in the presence of cone, H2SO4 to give compound (C) which is a dye. Identify (A) (B) and (C). Explain the reactions.

49. Predict A,B,C and D for the following reaction

50. A Monoobromoderivative (A) on treatment with KCN followed by acid hydrolysis and heating gives a monobasic acid (B) along with liberation of CO2 . (B) on heating with liquid ammonia followed by treating with Br2 /KOH  gives (c) which on treating with NaNO2 and HCl at low temperature followed by oxidation gives a monobasic acid (D) having molecular mass 74. Identify A to D.

51. How can the following coversion be effected?
i) Nitrobenzene ⇾ Nitrosobenzene
ii) Nitrobenzene ⇾ Azoxybenzene
iii) Nitrobenzene ⇾ Hydrazobenzene

52. Write a note on
(i) Carbylamine reaction
(ii) Mustard oil reaction
(iii) Acetylation of benzylamine
(iv) Formation of Schiff's base
(v) Diazotisation reaction

53. Write the structure of all possible dipeptides which can be obtained form glycine and alanine

54. Write a note on formation of α-helix .

55. Elucidate the structure of glucose.

56. List the importance of proteins in biological processes.

57. What are bio degradable polymers? Give examples.

58. Differentiate thermoplastic and thermosetting.

59. Write a note on drug target interaction.

60. Explain the classification of polymers based on their structure and mode of synthesis.