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

Define the following term:

Ferromagnetism

Draw the structures of major monohalo products in each of the following reactions :

Which halogen compound in the following pair will react faster in S_N2 reaction CH₃Br or CH₃I.

Which halogen compound in each of the following pairs will react faster in S_N2 reaction

(CH₃)₃ C – Cl or CH₃ – Cl

Write the type of magnetism observed when the magnetic moments are oppositely aligned and cancel out each other.

Write the type of magnetism observed when the magnetic moments are aligned in parallel and anti-parallel directions in unequal numbers.

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?