Science (English Medium) Class 12 - CBSE Question Bank Solutions

Explain the following with suitable examples: 

Antiferromagnetism

The two strands in DNA are not identical but are complementary. Explain.

Give two examples to show the anomalous behaviour of fluorine.

Write two uses of ClO₂.

Why are halogens coloured?

Write the reactions of F₂ with water.

With what neutral molecule is ClO⁻ isoelectronic? Is that molecule a Lewis base?

Arrange the following in the order of property indicated for the given set:

HF, HCl, HBr, HI - increasing acid strength.

Give reasons:Ferrimagnetic substances show better magnetism than antiferromagnetic substances.

Complete chemical reactions are:Cl₂ + H₂O →

Complete the following equations:

 KMnO₄ 

Arrange the following in the decreasing order of their reducing character :

HF, HCl, HBr, HI

Based on the type of particles of dispersed phase, give one example each of associated colloid and multimolecular colloid.

What is the difference between Nucleotide and Nucleoside? 

 Cl2 acts as a bleaching agent. 

Out of [CoF₆]^3- and [Co(en)₃]³⁺, which one complex is
(i) paramagnetic
(ii) more stable
(iii) inner orbital complex and
(iv) high spin complex
(Atomic no. of Co = 27) 

Give reason for the following :  
Sulphur in vapour state shows paramagnetic behaviour. 

Example of ferromagnetic substance is ____________.

Substances which are weakly repelled in magnetic field are known as ____________.

All those atoms or molecules which have an odd number of electrons are