CBSE CLASS XII
Q. 1. While antacids and antiallergic drugs interfere with the function of histamines, why do these not interfere with the function of each other?
Q. 2. Low level of noradrenaline is the cause of depression. What type of drugs are needed to cure this problem? Name two drugs.
Q. 3. Name the members of the lanthanoid series which exhibit +4 oxidation states and those which exhibit +2 oxidation states.
Q. 4. For the reaction A -> B the rate becomes 27 times when the concentration of A is increased 3 times. What is the order of reaction
Q. 5. What is meant by the term ‘broad spectrum antibiotics’? Explain.
Q. 6. Explain the term copolymerisation and give one example.
Q. 7. Write the free radical mechanism for the polymerisation of ethene.
Q. 8. Write the monomers used for .
Q. 9. Define the following
Q. 10. What is the difference between a nucleoside and a nucleotide?
Q. 11. Account for the following:
Q. 12. Discuss the nature of bonding in the following coordination entities on the basis of valence bond theory: [Co(C2O3)3]3– (iv) [CoF6]3–
Q. 13. Give evidence that [Co(NH3)5Cl]SO4 and [Co(NH3)5SO4]Cl are ionisation isomers.
Q. 14. What do you understand by activation of adsorbent? How is it achieved?Or
Q. 15. What role does adsorption play in heterogeneous catalysis? Or
Q. 16. A 5% solution (by mass) of cane sugar in water has freezing point of 271K. Calculate the freezing point of 5% glucose in water if freezing point of pure water is 273.15 K.
Q. 17. State Henry’s law and mention some important applications?
Q. 18. Resistance of conductivity cell filled with 0.1molL-1 KCl solution is 100 ohm. If the resistance of the same cell when filled with 0.02molL-1 KCl solution is 520 ohm. Calculate the conductivity & molar conductivity of 0.02molL-1 KCl solution. The conductivity of 0.1 molL-1 solution of KCl is 1.29Sm-1.
Q. 19. During nuclear explosion, one of the products is 90Sr with half-life of 28.1 years. If 1 u of 90Sr was absorbed in the bones of a newly born baby instead of calcium, how much of it will remain after 10 years if it is not lost metabolically.
Paper By Mr. Mahendra Kalra