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I

c r i b e t h e chemical method of separation of 1°, 2° and 3° amines

from their mixture by Hoffmann's method? [51

30. a) What is titrat ion? How is a suitable indicator selected for a particular

titration? [2+3]

b) Define order and molecularity of a reaction. A first order reaction isI

40% complete in 30 minutes .. Calculate the time require for 80%

completion of the reaction.

31 . Write short notes on any two:

. __. _ .

i) Laboratory preparation·of chloroform.

ii) Faraday's law of electrolysis.

iii) Electrochemical theory of rusting.

i) Extraction ofMercu ry.

,..,

~ " ' . ;·, ( "" .?

- - - r r -- ·

- - The End---

rr, -1

I

/

'·

f

""

[1+1+3]

[5+5]

' ? v - - S o ' - < ~ ( HISSAN PRE-BOARD EXAMINATION -2067[2011]

Grade: XII

Time: .3 hrs

Chemistry [212]

F.M.:75

P.M.: 27

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)

l . /P redict the molecular geometry of H20 based on VSEPR model? [2)

2. What is nucleophile? Explain why alkylhalide give alkyl cyanides

when treated with KCN,where as with AgCN alkylisocyanides are

obtained? f l+ l ]

y What is iodoform test? Write any two compounds which give positive

iodoform test. [ 1+I )

What happens when chloroform is treated with [1+1)

a) Acetone b)aq.NaOH

5. How can you convert phenol into ortho or para hydroxybenzaldehydc? 1216. Predict the major products in the following reactions;

a)

b)

CzHsOCzHs o,'l Atr >

CH30C2H5 PCJ,

Name the compound (A),(B),(C) and (D).

CH30H }' +I, A _ KCN ) B LtAIH. ) c

~ . ~

II+ II

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