PUC Science 2nd PUC Class 12 - Karnataka Board PUC Question Bank Solutions for Chemistry

Write the structures of A, B and C in the following:

Out of BaCl₂ and KCl, which one is more effective in causing coagulation of a negatively charged colloidal Sol? Give reason.

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