CBSE Class 12 Chemistry Sample paper 2014 Set E

1. Write the products obtained when benzyl phenyl ether is heated with HI.

2. Gases with high critical temperature are readily absorbed . Why?

3. Write the IUPAC name of the compound CH₂(Cl)COCH(CH₃)CONH₂

4. Which of the following compounds has a lone pair of electrons at the central atom?

H₂SO₃ , H₂SO₄

5. What type of linkage holds together the monomers of DNA?

6. Complete the following reaction: 

7. Write a non-exothermic reaction taking place in the blast furnace during extraction of iron.

8. Iodoform has antiseptic properties. Give one reason to support this.

9. KF has ccp structure. Calculate the ionic radius and F– ion if the side of cube or edge length is 400 pm. How many F– ions and octahedral voids are there in the unit cell?

10. Give reason :

(a) Why is Frenkel defect found in AgCl and not in the alkali metal halides?

(b) What is the difference between Phosphorus doped and Gallium doped Silicon semi-conductors?

11. Describe the construction of a H₂-O₂ fuel cell and the reactions taking place in it.

OR

Define the terms given below:

(a) Conductivity (b) Molar Conductivity What are their units?

12. State Raoult’s a law for a solution containing volatile liquids. Explain with suitable example, the concept of maximum boiling azeotropes.

13. Give chemical reactions in support of the following observations.

(a) Sulphuric acid has low volatility.

(b) Iodide ions can be oxidized by oxygen in acidic medium.

14. Propose mechanisms of the reaction taking place when

(a) (-) -2-Bromooctane reacts with sodium hydroxide to form (+)-octan- 2-ol.

(b) 2-Bromo pentane is heated with alc. KOH to form alkenes.

16. What is flux? What is the role of flux in the metallurgy of Iron and copper?

17. Neetu and Asha look organic compound synthesis as their chemistry project. They prepare benzene diazonium chloride and stored it at room temperature. Due to holiday, they start preparing azodye but it cannot be prepared. Then their friend Reena told them to prepare benzene diazonium chloride again and to use it immediately to prepare azo dye and they proceed accordingly and prepared azo dye successfully.

(i) Why azo dye is not a prepared from stored benzene diazonium chloride?

(ii) Write reaction involved in azo dye formation.

(iii) Write the values associated with the suggestion given by Reena.

18. Give reason:

(a) Nature of electrodes can also affect the products of electrolysis.

(b) Why does a dry cell become dead after a long time even if it has not been used?

(c) Conductivity decreases with decrease in concentration of electrolyte in a solution.

19 Write :

(a) Reaction involved in the preparation of a biodegradable polyester.

(b) Monomer unit of synthetic rubber (neoprene)

(c) One use of Nylon-6,6. 

Please refer to attatched file for CBSE Class 12 Chemistry Sample paper 2014 Set E