Subject

Chemistry

Class

CBSE 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

Download the PDF Sample Papers Free for off line practice and view the Solutions online.
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 Multiple Choice QuestionsShort Answer Type

21.

Arrange the following compounds in an increasing order of their solubility in water: 

C6H5NH2, (C2H5)2NH, C2H5NH2
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22.

What are biodegradable polymers?

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23.

Explain the following giving one example for each: 

(i) Reimer-Tiemann reaction. 

(ii) Friedel Craft’s acetylation of anisole.

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24.

How would you obtain 

(i) Picric acid (2, 4, 6-trinitrophenol) from phenol, 

(ii) 2-Methylpropene from 2-methylpropanol? 

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25.

What is essentially the difference between α-form of glucose and β-form of glucose? Explain.

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26. Describe what you understand by the primary structure and secondary structure of proteins.
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27.

Mention two important uses of each of the following:

 (i) Bakelite

 (ii) Nylon 6

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28.

 Explain why an alkylamine is more basic than ammonia.


(a) The basicity of amines depends on the +I effect of the alkyl groups. With increase in alkyl group the +I effect will increase which will increase the ease of donation of lone pair electron. Amine will accept a proton and from cation will be stabilized in water by salvation (by hydrogen bonding).better the salvation by hydrogen bonding higher will be the basic strength.
Hence, alkyl amine is more basic than ammonia 
CH3NH2 > NH3

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29.

How would you convert? 

(i) Aniline to nitrobenzene 

(ii) Aniline to iodobenzene

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 Multiple Choice QuestionsLong Answer Type

30.

(a) Differentiate between molarity and molality for a solution. How does a change in temperature influence their values? 

(b) Calculate the freezing point of an aqueous solution containing 10.50 g of MgBr2in 200 g of water. (Molar mass of MgBr2 = 184 g) (Kf for water = 1.86 K kg mol-1

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