12th class chemistry old paper Download PDF from given link

12th class chemistry paper set-B jk Bose old paper 

(Long Answer Type Questions) 5 each

1.Explain the terms :
(i) molarity (ii) molality (iii) normality (iv) mole fraction (v) parts per million (PPm)

                               Or

What is depression in freezing point ? Derive the relationship between depression in freezing point and molecular mass of a non-volatile solute.

2.. State and explain Faraday’s laws of electrolysis. What is meant by electro chemical equivalent ?

                           Or
What are fuel 'cells ? Describe H2 -02 fuel cell. Give advantages of fuel cells.

3. Name the elements of group 15. Give their electronic configuration. List the various oxidation states of nitrogen and give an example in each case.