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.
Advertisement

 Multiple Choice QuestionsShort Answer Type

11.

On the basis of crystal field theory, write the electronic configuration for d4 ion if ∆o < P ?

6322 Views

12.

Write the hybridization and magnetic behaviour of the complex [Ni(CO)4].

(At.no. of Ni = 28)

3252 Views

13.

Calculate emf of the following cell at 25 °C:

 Fe | Fe2+(0.001 M) || H+ (0.01 M) | H2 (g) (1 bar) | Pt(s)

 E°(Fe2+ | Fe) = –0.44 V E°(H+ | H2 ) = 0.00 V

2565 Views

14.

Give reasons for the following observations:

Leather gets hardened after tanning

2281 Views

Advertisement
Advertisement

15.

Give reasons for the following observations:

Lyophilic sol is more stable than a lyophobic sol.


The stability of lyophilic sols is a result of two factors, the presence of a charge and the solvation of colloidal particles. On the other hand, the stability of lyophobic sols is only because of the presence of a charge. Thus, the lyophilic sol is more stable than lyophobic sol due to the extensive solvation.

1479 Views

Advertisement
16.

Give reasons for the following observations:

It is necessary to remove CO when ammonia is prepared by Haber's process.

1340 Views

17.

3.9 g of benzoic acid dissolved in 49 g of benzene shows a depression in freezing point of 1.62 K. Calculate the van't Hoff factor and predict the nature of solute (associated or dissociated).


(Given: Molar mass of benzoic acid = 122 g mol-1, Kf for benzene = 4.9 K kg mol-1

4517 Views

18.

Indicate the principle behind the method used for the refining of zinc.

2921 Views

Advertisement
19.

What is the role of silica in the extraction of copper?

1489 Views

20.

Which form of the iron is the purest form of commercial iron?

1470 Views

Advertisement