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

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 Multiple Choice QuestionsShort Answer Type

1.

How many atoms constitute one unit cell of a face-centered cubic crystal? 

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2.

Name the method used for the refining of Nickel metal?

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3.

What is the covalency of nitrogen in N2O5

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4.

Arrange the following in increasing order of their basic strength in aqueous solution: 

 CH3NH2, (CH3)3N, (CH3)2NH


With the increase in the alkyl group, the +I effect will increase which will increase the ease of donation of lone pair electron. But in water one other factor is controlling the strength of basicity.

 Amine will accept a proton and from cation will be stabilised in water by salvation (by hydrogen bonding) better the salvation by hydrogen bonding higher will be the basic strength.

 (CH3)3N<CH3NH2< (CH3)2NH

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5.

18 g of glucose, C6H12O6 (Molar Mass = 180 g mol-1) is dissolved in 1 kg of water in a saucepan. At what temperature will this solution boil? 

 (Kb for water = 0.52 K kg mol-1, boiling point of pure water = 373.15 K)

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6.

The conductivity of 0.20 M solution of KCl at 298 K is 0.025 S cm-1. Calculate its molar conductivity?

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7.

Write the dispersed phase and dispersion medium of the following colloidal systems: 

 (i) Smoke (ii) Milk

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8.

What are lyophilic and lyophobic colloids? Which of these sols can be easily coagulated on the addition of small amounts of electrolytes?

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9.

Write the differences between physisorption and chemisorption with respect to the following:

(i) Specificity

(ii) Temperature dependence

(iii) Reversibility and

(iv) Enthalpy change

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10.

Which solution is used for the leaching of silver metal in the presence of air in the metallurgy of silver? 

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