New ! Chemistry MCQ Practise Tests



Important 2 Mark Book Back Questions (New Syllabus) 2020

12th Standard

    Reg.No. :
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Chemistry

Time : 01:00:00 Hrs
Total Marks : 32

    Part A

    16 x 2 = 32
  1. Boron does not react directly with hydrogen. Suggest one method to prepare diborane from BF3.

  2. Explain why fluorine always exhibit an oxidation state of -1?

  3. Justify the position of lanthanoids and actinoids in the periodic table.

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

  5. Explain briefly seven types of unit cell.

  6. Describe the graphical representation of first order reaction.

  7. What is the order with respect to each of the reactant and overall order of the following reactions?
    a) 5Br-(aq)+BrO3-(aq)+6H+(aq) ➝3Br2(l)+3H2O(l)
    The experimental rate law is Rate = k [Br][BrO3][H+]2
    b) CH3CHO(g)\(\overset { \Delta }{ \longrightarrow } \) CH4(g)+CO(g) the experimental rate law is
    Rate =K[CH3CHO]\(\frac{3}{2}\)

  8. The concentration of hydroxide ion in a water sample is found to be 2.5 × 10-6M. Identify the nature of the solution.

  9. Why does conductivity of a solution decrease on dilution of the solution.

  10. A conductivity cell has two platinum electrodes separated by a distance 1.5 cm and the cross sectional area of each electrode is 4.5 sq cm. Using this cell, the resistance of 0.5 N electrolytic solution was measured as 15 Ω. Find the specific conductance of the solution.

  11. Differentiate physisorption and chemisorption.

  12. Predict the major product, when 2-methyl but -2-ene is converted into an alcohol in each of the following methods.
    (i) Acid catalysed hydration
    (ii) Hydroboration
    (iii) Hydroxylation using Baeyer's reagent

  13. State the laws of reflection.

  14. Identify compounds A, B and C in the following sequence of reactions.
    i) \({ C }_{ 6 }{ H }_{ 5 }NO_{ 2 }\overset { Fe/HCL }{ \longrightarrow } A\overset { HN{ O }_{ 2 } }{ \underset { 273K }{ \longrightarrow } } B\overset { { C }_{ 6 }{ H }_{ 5 }OH }{ \longrightarrow } C\)
    ii) \({ C }_{ 6 }{ H }_{ 5 }N_{ 2 }cl\overset { CuCN }{ \longrightarrow } A\overset { H_{ 2 }O/H^{ + } }{ \longrightarrow } B\overset { NH_3 }{ \longrightarrow } C\)
    iii) \({ C }{ H }_{ 3 }{ C }{ H }_{ 2 }I\overset { NaCN}{ \longrightarrow } A\overset {OH^-}{ \underset {Partial hydrolysis}{ \longrightarrow } } B\overset {NaOH+Br_2 }{ \longrightarrow } C\)
    iv) \({ C }{ H }_{ 3 }NH_{ 2 }\overset { CH_3 Br }{ \longrightarrow } A\overset { CH_{ 3 }COCl}{ \longrightarrow } B\overset { B_2H_6 }{ \longrightarrow } C\)
    v) \({ C }_{ 6 }{ H }_{ 5 }NH_{ 2 }\overset { (CH_{ 3 }CO)_{ 2 }O }{ \underset { Pyridine }{ \longrightarrow } } A\overset { HNO_{ 3 } }{ \underset { H_{ 2 }SO_{ 4 },288K }{ \longrightarrow } } B\overset { { H }_{ 2 }O/{ H }^{ + } }{ \longrightarrow C } \)
    vi) 

    vii) \({ C }{ H }_{ 3 }CN_{ 2 }NC\overset { HgO }{ \longrightarrow } A\overset { H_{ 2 }O }{ \longrightarrow } B\overset { i) NaN{ O }_{ 2 }/HCL }{ \underset { ii){ H }_{ 2 }O }{ \longrightarrow } } \)

  15. Name the Vitamins whose deficiency cause i) rickets ii) scurvy

  16. Write a note on synthetic detergents

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