8/7/2019 Hissan Pre-Board Exam 2067Chemistry Xii

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HISSAN PRE-BOARD EXAMINATION 2011 [2067] CHEMISTRY XII

P+I2 KCN

HISSAN PRE-BOARD EXAMINATION 2067 [2011]

Grade: XII F.M.: 75

Time: 3 hrs P.M.: 27

Chemistry [212]

Candidates are required to give their answers in their own words as far as practicable. The figures in the

margin indicate full marks.

Attempt all the questions as instructed:

Group- A

Attempt any fifteen questions: [15x2=30]

1. Predict the geometry of H2O based on VSEPR model? [2]2. What is nucleophile? Explain why alkyhalide give alkyl cyanides when treated with KCN, whereas with

AgCN alkylisocyanides are obtained? [1+1]

3. What is iodoform test? Write any two compounds which give positive iodoform test. [1+1]4. What happens when chloroform is treated with [1+1]

a. Acetone b. aq. NaOH5. How can you convert phenol into ortho or para hydroxybenzaldehyde? [2]6. Predict the major products in the following reactions: [1+1]

C2H5O C2H5

CH3OC2H5

7. Name the compound (A), (B), (C) and (D). [1+1]CH3OH A B C

8. Why is ethylamine more basic than acetamide? [2]9. Write an expression of Perkin condensation reaction. [2]10.Write down the open chain structure of glucose and fructose. Which one of this gives Fehling solution

test? [2]

11.What is peptide bond? What happens when tri-peptide is acid hydrolysed? Give chemical reaction.[1+1]

12.Define thermoplastic and thermosetting plastic with example. [1+1]13.How many Faraday of electricity are required to discharge Mg2+ and Fe3+?14.What is salt bridge? Write the function of salt bridge. [1+1]15.Calculate the pH of 4.5 x 10-8 M HCl ? [1+1]16.What is meant by spontaneous process and what is the criterion for spontaneity of reaction? [1+1]17.Define activation energy and threshold energy. Draw energy profile diagram also. [1+1]18.What is the role of CO in the extraction of iron? [2]19.What is meant by the term Galvanization? Give one of its important uses. [2]20.Give chemical reactions showing amphoteric behavior of litharge. [2]

Group- B

Attempt any five questions: [5x5=25]

21.Compound (A), C7H9N, undergoes diazotization with NaNO2/HCl at 00C to give (B), C7H7N2Cl. Compound(B) on treatment with CuCl/HCl gives (C), C7H7Cl. Compound (C) is an ortho- disubstituted benzene

PCl5

O2 / Air

LiAlH4

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8/7/2019 Hissan Pre-Board Exam 2067Chemistry Xii

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HISSAN PRE-BOARD EXAMINATION 2011 [2067] CHEMISTRY XII

which on oxidation followed by heating with soda-lime gives (D), C6H5Cl. Draw structures of (A), (B), (C)

and (D) with their name. [5]

22.Describe the preparation of ethoxyethane in laboratory? [5]23.Describe how can you distinguish between propanol, propan-2-ol and tert-butyl alcohol by Victors

Meyers method. [5]

24.Define the term Faraday. Calculate the weight of copper metal deposited during the passage of 3amperes current through a solution of copper sulphate for 60 minnutes. (atomic mass of Cu= 63.5)

[1+4]

25.What is meant by normality factor? Calculate the value of x when 12.6 gm of hydrated oxalic acid(H2C2O4.XH2O) was dissolved in water and the solution was made 1000ml, 15ml of this solution

required 30ml of N/10 NaOH for complete neutralization. [1+4]

26.State second law of thermodynamics. Calculate the enthalpy of formation of N2O5 (g) on the basis ofthe following data. [1+4]

a. 2NO (g) + O2 (g) 2NO2 (g) ; H0 = -114.0 KJb. 4NO2 (g) + O2 (g) 2N2O5 (g) ; H0 = -102.6 KJc. N2 (g) + O2 (g) 2NO (g) ; H0 = +180.4 KJ

27.Give the preparation, properties and uses of white vitrol. [2+2+1]Group-C

Attempt any two questions: [2x10=20]

28.How is nitrobenzene prepared in laboratory in pure and dry state?What are the different productsobtained by reduction of nitrobenzene in different medium? [6+4]

29.a) Consider a reactionA B C D E

The compound E is primary alcohol that gives iodoform test. Identify A, B, C, D and E with logical

explanation. [5]

b) Describe the chemical method of seperation of 10, 20, 30amines from the mixture by Hoffmannsmethod? [5]

30.a) What is titration? How is suitable indicator selected for a particular titration? [2+3]b) Define order and molecularity of a reaction. A first order reaction is 40% complete in 30 minutes.

Calculate the time required for 80% completion of the reaction. [1+1+3]

31.Write short notes on any two: [5+5]a. Laboratory preparation of chloroformb. Faradays Law of Electrolysisc. Electrochemical theory of rustingd. Extraction of mercury

THE END

SOCl2 NH3

NaNO2/HCl

Br2/KOH

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