Subject

Chemistry

Class

ICSE Class 12

Pre Boards

Practice to excel and get familiar with the paper pattern and the type of questions. Check you answers with answer keys provided.

Sample Papers

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 Multiple Choice QuestionsShort Answer Type

31.

(i) State the two necessary conditions for a compound to show geometrical isomerism.    

(ii) Why is meso-tartaric acid optically inactive ?

(iii) Write the structure of three compounds which have the same molecular formula of C4H8O but have different functional groups.

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32. Complete the following reactions and name the intermediate products A, B and C. 

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33.

(i) Give any one example of a cross-linked synthetic polymer. 

(ii) With reference to the polymer named by you :

(1) Write the compounds from which it is prepared.

(2) Give one physical property of the cross-linked synthetic polymer.

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 Multiple Choice QuestionsLong Answer Type

34.

Write the relevant equations to convert:  

(i) Fructose to osazone.

(ii) Acetic acid to acetone.

(iii) Acetyl chloride to acetic anhydride.

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35.

Give one test each to distinguish between : 

(i) Acetaldehyde and formaldehyde.

(ii) Acetone and acetic acid.

(iii) Starch and cellulose.


straight i right parenthesis space Acetaldehyde space show space iodoform space test colon

CH subscript 3 CHO space plus 4 NaOH space plus 3 straight I subscript 2 space rightwards arrow stack CHI subscript 3 with Yellow space ppt. below space plus HCOONa space plus 3 straight H subscript 2 straight O space plus 3 NaI
while space formaldehyde space does space not space show space this space thest

ii right parenthesis space CH subscript 3 COOH space plus NaHCO subscript 3 space rightwards arrow space CH subscript 3 COONa space plus straight H subscript 2 straight O space plus CO subscript 2
It space gives space brisk space effervescence space due space to space evolution space of space CO subscript 2
Acetone space does space not space give space effervescence space with space NaHCO subscript 3

iii) Cellulose is not readily hydrolysed so readily as starch but on heating with dilute sulphuric acid and under pressure give D-glucose. 
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36. Write balanced chemical equations for the following and name the reactions occurring in each case :    

(i) Benzaldehyde reacts with an alcoholic solution of potassium cyanide.

(ii) Aniline is warmed with chloroform and alcoholic potassium hydroxide.

(iii) Propanone is treated with iodine and excess of alkali and warmed.

(iv) Benzoic acid is treated with soda lime.

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