CBSE Guess > Papers > Question Papers > Class XII > 2005 > Chemistry > Delhi Set-III

CHEMISTRY 2005 (Set-III Delhi)

Except for the following questions, all the remaining questions have been asked in Set I and Set II.

Q. 12. Write the names and structures of the monomers used for getting the following polymers: 2

(i) PVC

(ii) PMMA

Q. 18. What are the two classes of emulsions? Give one example of each class State one activity to test the type of an emulsion. 3

Q. 23. The radioactive isotope Co can be made by both an (n, p) and an (n, ) reaction For each reaction indicate the appropriate target nucleus If the half-life of Co is 7 years, calculate the dacay constant for it. 3

Q. 24. What are carbon fibres and what properties make them specially useful? Write two uses of carbon fibres. 3

Q. 26. (a) Assign a reason for each of the following statements:

(i) Unlike In⁺ TI⁺ is stable with respect to disproportionation reaction:

(ii) Pérehioric acid is a stronger acid than sulphuric acid.

(iii) Of all the noble gases only Xenon is known to form established chemi cal compounds.

(b) Write the structural formulae for the following: 3, 2

(i) SF₄

(ii) XeO₃

Or

 (a) Assign a reason for each of the following statements:

(i) Anhydrous AICI₃ acts as a catalyst in many organic reactions.

(ii) All the bonds in a molecule of PCI₅ are not equal.

(iii) Hydrogen fluoride is a weaker acid than hydrogen chloride in aqueous solution.

(b) Write structure of the following molecules:

(i) IF₅

(ii) XeOF₃

Q. 27. (a) How are the lipids classified? Give one example of each class.

(b) Name the deficiency diseases resulting from lack of Vitamins A and E in the diet. 5

Or

(a) Define vitamins and state their classification. List two vitamins of each class.

(b) What are enzymes? State the activity of an enzyme.