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

Give reasons for the following observations: Leather gets hardened after tanning.

Write the structures of the following molecule: 

H₂SO₃

Define the following term : Brownian movement

Draw the structures of the following molecules: H₂S₂O₈

Give the structures of A, B and C in the following reaction:

A group 14 element is to be converted into n-type semiconductor by doping it with a suitable impurity. To which group should this impurity belong?

What is a semiconductor?

Non-stoichiometric cuprous oxide, Cu₂O can be prepared in laboratory. In this oxide, copper to oxygen ratio is slightly less than 2 : 1. Can you account for the fact that this substance is a p-type semiconductor?

Classify each of the following as being either a p-type or a n-type semiconductor:

1. Ge doped with In 
2. B doped with Si

Explain the following with suitable examples:

12-16 group compounds

What modification can you suggest in the Hardy-Schulze law?

Explain what is observed when a beam of light is passed through a colloidal sol.

Explain what is observed when an electrolyte NaCl is added to hydrated ferric oxide sol.

Explain what is observed when an electric current is passed through a colloidal sol?

Explain the term Electrophoresis

Explain the terms Coagulation

Explain the terms Dialysis 

Explain the term Tyndall effect.

What happens when sulphur dioxide is passed through an aqueous solution of Fe(III) salt?