CBSE Class 12 Chemistry Question paper 2006 (2)

 CBSE Class 12 Chemistry Question paper 2006 (2). Students can download the last year question papers using the link below. Free download of examination question papers with solutions.Last 10 year question papers should be practised to get better marks in examinations.

Q.1. Name the non-stoichiometric point defect responsible for colour in alkali halides.

Q.2. Define ‘mole fraction’ of a substance in a solution.

Q.3. A reaction is 50% complete in 2 hours and 75% complete in 4 hours. What is the order of the reaction?

Q.4. Write the IUPAC name of CH₃COCH ₂ COCH _3.

Q.5. Give a chemical test to distinguish between a primary and a secondary amine.

Q.6. Account for the following:

i. N2 has higher bond dissociation energy than NO.

ii. N2 and CO both have same bond order but CO is more reactive than N₂.

Q.7. At absolute zero, an exothermic reaction is always spontaneous but at emperatures above absolute zero, we have to consider both enthalpy and entropy before we can predict spontaneity.Why?

Q.8. Write the chemical equations involved in the preparation of the following:

i. XeF₄

ii. H₃PO₃

Q.9. Why is the +2 oxidation state of manganese quite stable, while the same is not true for iron? [Mn= 25,Fe = 26]

Q.10. Differentiate between conformation and configuration in open chain molecules by giving one example each.

Q.11. Give reasons for the following:

a. Ortho-nitrophenol is more acidic than ortho-methoxyphenol.

b. Glycerol is used in cosmetics.

Q.12. Write the structures of monomoers used and one use of each of the following polymers:

a. Teflon

b. Buna-N

Or

What are biodegradale polymers? Give two examples.

Q.13. What is meant by dual nature of electrons? Calculate the energy and wavelength of the photon emitted by hydrogen atom when the electron makes a transition from n =2 to n = 1. Given that the ionization potential is 13.6 eV. [1 eV =1.6 x 10—19 J]

Q.14. Calculate the distance between Na+ and Cl— ions in NaCl crystal if its density is 2.165 g cm-3. [Molar mass of NaCl= 58.5 g mole-1; NA = 6.02 x 1023 moI-1] (3)

Q.15. a. Urea forms an ideal solution in water. Determine the vapour pressure of an aqueous solution containing 10% by mass of urea at 40° C.(Vapour pressure of water at 40° C = 55.3 mm of Hg)

b. Why is freezing point depression of 0.1 M sodium chloride solution nearly twice that of 0.1 M glucose solution?

Q.16. How is the concept of coupling reactions useful in explaining the occurrence of nonspontaneous

thermochemical reactions? Explain giving an example.

Q.17. a. In which of the following does adsorption take place and why?

i. Silica gel placed in the atmosphere saturated with water.

ii. Anhydrous CaCl₂ placed in the atmosphere saturated with water.

b. How does BF₃ act as a catalyst in industrial process?

c. Give an example of shape-selective catalysis.

Please click the link below to download pdf file of CBSE Class 12 Chemistry Question paper 2006 (2).