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#### Model 2 Mark Book Back Questions (New Syllabus) 2020

12th Standard EM

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Chemistry

Time : 01:00:00 Hrs
Total Marks : 36

Part A

18 x 2 = 36
1. What is the difference between minerals and ores?

2. Boron does not react directly with hydrogen. Suggest one method to prepare diborane from BF3.

3. Give the uses of helium.

4. What are actinides? Give three example

5. [CuCl4]2- exists while [Cul4]2- does not exist why?

6. Distinguish tetrahedral and octahedral voids.

7. Explain the rate determining step with an example.

8. Discuss the Lowery – Bronsted concept of acids and bases.

9. Calculate the concentration of OH- in a fruit juice which contains $2\times10^{-3}$ M, H3O+ ion. Identify the nature of the solution.

10. Why is anode in galvanic cell considered to be negative and cathode positive electrode?

11. The resistance of a conductivity cell is measured as 190 Ω using 0.1M KCl solution (specific conductance of 0.1M KCl is 1.3 Sm-1) . When the same cell is filled with 0.003M sodium chloride solution, the measured resistance is 6.3KΩ. Both these measurements are made at a particular temperature. Calculate the specific and molar conductance of NaCl solution. Given that

12. Which will be adsorbed more readily on the surface of charcoal and why; NH3 or CO2?

13. Draw the major product formed when 1-ethoxyprop-1-ene is heated with one equivalent of HI

14. Identify X and Y.
${ CH }_{ 3 }CO{ CH }_{ 2 }{ CH }_{ 2 }COO{ C }_{ 2 }{ H }_{ 5 }\overset { { CH }_{ 3 }MBgr }{ \longrightarrow } X\overset { { H }_{ 3 }{ O }^{ + } }{ \longrightarrow } Y$

15. Give the characteristics of image formed by a plane mirror.

16. There are two isomers with the formula  CH3NO2. How will you distinguish between them?

17. Give any three difference between DNA and RNA

18. How do antiseptics differ from disinfectants?