Science (English Medium) इयत्ता १२ - CBSE Question Bank Solutions for Chemistry

Action of soap is due to emulsification and micelle formation. Comment.

Give four uses of emulsions.

What products would be formed when a nucleotide from DNA containing thymine is hydrolysed?

What are the different types of RNA found in the cell?

Write the important functional differences between DNA and RNA.

Mention three areas in which H₂SO₄ plays an important role.

Why is `K_(a_2) "<<" K_(a_1)` for `H_2SO_4` in water?

Describe the manufacture of H₂SO₄ by contact process?

Write balanced equations for NaCl is heated with sulphuric acid in the presence of MnO₂

Give reasons : Silicon on doping with Phosphorous forms n-type semiconductor.

When concentrated sulphuric acid was added to an unknown salt present in a test tube a brown gas (A) was evolved. This gas intensified when copper turnings were added to this test tube. On cooling, the gas (A) changed into a colourless solid (B).

1) Identify (A) and (B).

2) Write the structures of (A) and (B).

3) Why does gas (A) change to solid on cooling?

Give one example each of 'oil in water' and 'water in oil' emulsion.

What type of linkage is responsible for the formation of proteins?

Write the product formed when glucose is treated with HI ?

 Complete and balance the following equations: 
S+H₂SO₄(conc.)  → 

Answer the following question.
What is the difference between an emulsion and a gel?

A group of 14 elements is converted into n-type semiconductor by doping it with:

Group 14 element is converted to p-type semiconductor by doping it with:

In n-type semiconductor, current is carried by ____________.

Which transition metal oxide has appearance and conductivity like that of copper?