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

What type of substances would make better permanent magnets, ferromagnetic or ferrimagnetic. Justify your answer.

Analysis shows that nickel oxide has the formula Ni_0.98O_1.00. What fractions of nickel exist as Ni²⁺ and Ni³⁺ ions?

Explain the following with suitable examples:

Paramagnetism

Explain the following with suitable examples:

Ferrimagnetism

Explain the following with suitable examples: 

Antiferromagnetism

How are vitamins classified? Name the vitamin responsible for the coagulation of blood.

Why are vitamin A and vitamin C essential to us? Give their important sources.

Give plausible explanation for the following:

During the preparation of esters from a carboxylic acid and an alcohol in the presence of an acid catalyst, the water or the ester should be removed as soon as it is formed.

Complete the synthesis by giving missing starting material, reagent or product.

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.