12th Chemistry 2013 Guess & Sample Question Paper

 12th Chemistry 2013 Guess & Sample Question Paper

                        12th Chemistry 2013 Guess & Sample Question Paper

Guess Paper 2013

Subject : Chemistry

Class: XIIth

                                            

M.M:70                                                                                                                                                           Time:3hr

All Questions are compulsory.

Q.No. 1 to 8 carry  1 mark each.

Q.No. 9 to 18 carry 2 marks each.

Q.No 19 to 27 carry 3 marks each.

             Q.No.28 to 30 carry 5 marks each.                                          

 

 

 

  1. Express the rate of following reaction in terms of disappearance of hydrogen in the reaction.

       3H2(g) + N2(g)                 2NH3(g)

 

  1. What is peptisation?

 

  1. Write Reimer Tiemann reaction.

 

 

  1. Why is CO stronger ligand that Cl-.

 

  1. Write structure of 2-(2-Bromophenyl)butane.

 

 

  1. Complete the reaction C6H6+R COCl

 

  1. Why pentahalides more covalent than trihalides?

 

 

  1. What is difference between nucleoside and nucleotide?

 

  1. Explain the following-

(a)   Gattermann Koch reaction

              (b)   HVZ reaction

 

         10.      How will you distinguish between the following.

              (a)  Pentan-2-one and pentan-3-one

              (b)  Aniline and N-Methylaniline

 

         11.      What is crystal field splitting energy?How does the magnitude of splitting decide the actual configuration of d-

                     orbitals in an octahedral field for a  coordination entity.

 

         12.       You work in a large university physical plant department which overseas the day to day operation of the

                     Building on campus.  The university  currently maintain 14 days scale air conditioning units that still use CFC as

                     refrigerant. These units were  installed well before 1996 ban on CFC production A member of the budget                  

                     committee comes to you before she is      concerned  about the potential cost of replacing so many units. She ask

                     these questions.

(a)    Since a cooling unit is sealed why does the continued use of CFC pose any risk to the environment?

(b)   Can’t the university simply buy a different refrigerant to replace the CFC’s and use. It in existing unit?

(c)    What would be the concern associated with such refrigerant replaced?

 

         13.       Write the formula and the structure of noble gas species which are  

                      isostructural with

(a)    ICl4-               (b) BrO3-

 

         14.        Explain

                      (a)     Why is dioxygen a gas but sulphur a solid?

                      (b)     Why are interhalogen compounds more reactive than hologens?

 

        15.          Distinguish between rate expression and rate constant of a reaction.

 

        16.          An alloy of gold and cadmium crystallizes with a cubic structure in which gold atom occupy the corners and

                      cadmium atoms fit into the face centres.  Assign formula of this alloy.

 

        17.        An element x Crystallizes in fcc structure. 208g of it has 4.28X1024atoms.

                     Calculate edge length of unit cell if the density of X is 7.2g/an3.

 

        18.        Determine E0 and ∆G0 for the reaction.

                    Zn(s)+Ag2O(s)+H2o(l)           Zn++ (ag)+2 Ag(s)+20H-(ag)

                      (given E0Ag+/Ag+=0.80V E0Zn++/2n=-0.76v)

 

        19.        Write short note on-

                      (a) Multimalecular colloids

                      (b) Macromolecular colloids

                      (c)Associated colloids

 

       20.          (a) What is the significance of 6,6 in Nylon-6,6?

                      (b) Write name and structure of monomer of Dacron and Teflon.

 

       21.          (a) Why is the use of aspartame limited to cold foods and drinks only?

                      (b) Name two antifertility drugs?

 

       22.          (a) What is the structure difference between starch and cellulose?

                      (b) Why can’t vitamin C stored in human body?

                      (c) Name the vitamin whose deficiency cause muscular weakness?

      23.                Complete the reactions

      24.            (a) What are ambident nucleophiles?

                       (b)  How will you convert

                           (i) Ethanol to but-1-yne

                           (ii) But-1-ene to But-2-ene

     25.             (a) How is cast iron differ from pig iron?

                       (b) What is the role of graphite in electrometallurgy of aluminium?

                       (c) What is the role of flux in metallurgical process?

 

     26.             The vapour pressure of water is 12.3 kpa at 300K. Calculate vapour pressure of 1 molal solution of a non-

                      volatile solute in it.

 

     27.             (a) Write IUPAC name of (CH3CH2)2NCH3

                       (b) How can the activating effect of –NH2 group be controlled?

                       (c) How will you convert methanamine to ethanamine?

 

     28.             (a) Draw structure of XCO3 and XeoF4

                       (b) How does Pcl5 exists in solid state?

                       (c) Why is Ka2  Ka1 for H2So4 in H2?

                                                   Or

(a)       Draw structure of H2P2O7

(b)    Why is white phosphorous less stable?

(c)       Whydoes R3P=0 exists but R3N=0 doesn’t?

 

 

    29.              (a)  What is hydroboration oxidation reaction – give an example .

                      (b)   Draw structure of 3-Cyclohexylpentan-3-ol.

                      (c)   How will you convert

                           (i) Ethyl magnesium chloride to propan-1-ol

                           (ii) Methyl magnesium bromide to 2-methylpropan-2-ol

                                  Or

(a)    Write mechanism of hydration of ethane.

(b)    How will you convert eumane to phenol.

(c)     How will you synthesized the following from appropriate alkene?

 

30.                (a)  Why is actinoid contraction is   greater from element to element than  lanthanoid contraction?

(b)   Complete the reaction

                            Cr2O7­­--+I-             

(c)    Calculate spin only magnetic moment of M++ (Z=24).

(d)   Explain why Ce4+ is strong oxidizing agent?

 

                                              Or

(a)    What is lanthanoid contraction and their consequences

(b)   Givereason why d1 Configuration is very unstable in ions

(c)     Why is highest oxidation state ofa metal exhibited in its oxide or fluoride only?

(d)    Why transition elements act as good catalyst.

   

 

 

                                                                                                             

 

 

 







Subject : Chemistry

Class: XIIth

                                            

M.M:70                                                                                                                                                           Time:3hr

All Questions are compulsory.

Q.No. 1 to 8 carry  1 mark each.

Q.No. 9 to 18 carry 2 marks each.

Q.No 19 to 27 carry 3 marks each.

             Q.No.28 to 30 carry 5 marks each.                                          

 

 

 

  1. Express the rate of following reaction in terms of disappearance of hydrogen in the reaction.

       3H2(g) + N2(g)                 2NH3(g)

 

  1. What is peptisation?

 

  1. Write Reimer Tiemann reaction.

 

 

  1. Why is CO stronger ligand that Cl-.

 

  1. Write structure of 2-(2-Bromophenyl)butane.

 

 

  1. Complete the reaction C6H6+R COCl

 

  1. Why pentahalides more covalent than trihalides?

 

 

  1. What is difference between nucleoside and nucleotide?

 

  1. Explain the following-

(a)   Gattermann Koch reaction

              (b)   HVZ reaction

 

         10.      How will you distinguish between the following.

              (a)  Pentan-2-one and pentan-3-one

              (b)  Aniline and N-Methylaniline

 

         11.      What is crystal field splitting energy?How does the magnitude of splitting decide the actual configuration of d-

                     orbitals in an octahedral field for a  coordination entity.

 

         12.       You work in a large university physical plant department which overseas the day to day operation of the

                     Building on campus.  The university  currently maintain 14 days scale air conditioning units that still use CFC as

                     refrigerant. These units were  installed well before 1996 ban on CFC production A member of the budget                  

                     committee comes to you before she is      concerned  about the potential cost of replacing so many units. She ask

                     these questions.

(a)    Since a cooling unit is sealed why does the continued use of CFC pose any risk to the environment?

(b)   Can’t the university simply buy a different refrigerant to replace the CFC’s and use. It in existing unit?

(c)    What would be the concern associated with such refrigerant replaced?

 

         13.       Write the formula and the structure of noble gas species which are  

                      isostructural with

(a)    ICl4-               (b) BrO3-

 

         14.        Explain

                      (a)     Why is dioxygen a gas but sulphur a solid?

                      (b)     Why are interhalogen compounds more reactive than hologens?

 

        15.          Distinguish between rate expression and rate constant of a reaction.

 

        16.          An alloy of gold and cadmium crystallizes with a cubic structure in which gold atom occupy the corners and

                      cadmium atoms fit into the face centres.  Assign formula of this alloy.

 

        17.        An element x Crystallizes in fcc structure. 208g of it has 4.28X1024atoms.

                     Calculate edge length of unit cell if the density of X is 7.2g/an3.

 

        18.        Determine E0 and ∆G0 for the reaction.

                    Zn(s)+Ag2O(s)+H2o(l)           Zn++ (ag)+2 Ag(s)+20H-(ag)

                      (given E0Ag+/Ag+=0.80V E0Zn++/2n=-0.76v)

 

        19.        Write short note on-

                      (a) Multimalecular colloids

                      (b) Macromolecular colloids

                      (c)Associated colloids

 

       20.          (a) What is the significance of 6,6 in Nylon-6,6?

                      (b) Write name and structure of monomer of Dacron and Teflon.

 

       21.          (a) Why is the use of aspartame limited to cold foods and drinks only?

                      (b) Name two antifertility drugs?

 

       22.          (a) What is the structure difference between starch and cellulose?

                      (b) Why can’t vitamin C stored in human body?

                      (c) Name the vitamin whose deficiency cause muscular weakness?

      23.                Complete the reactions

      24.            (a) What are ambident nucleophiles?

                       (b)  How will you convert

                           (i) Ethanol to but-1-yne

                           (ii) But-1-ene to But-2-ene

     25.             (a) How is cast iron differ from pig iron?

                       (b) What is the role of graphite in electrometallurgy of aluminium?

                       (c) What is the role of flux in metallurgical process?

 

     26.             The vapour pressure of water is 12.3 kpa at 300K. Calculate vapour pressure of 1 molal solution of a non-

                      volatile solute in it.

 

     27.             (a) Write IUPAC name of (CH3CH2)2NCH3

                       (b) How can the activating effect of –NH2 group be controlled?

                       (c) How will you convert methanamine to ethanamine?

 

     28.             (a) Draw structure of XCO3 and XeoF4

                       (b) How does Pcl5 exists in solid state?

                       (c) Why is Ka2  Ka1 for H2So4 in H2?

                                                   Or

(a)       Draw structure of H2P2O7

(b)    Why is white phosphorous less stable?

(c)       Whydoes R3P=0 exists but R3N=0 doesn’t?

 

 

    29.              (a)  What is hydroboration oxidation reaction – give an example .

                      (b)   Draw structure of 3-Cyclohexylpentan-3-ol.

                      (c)   How will you convert

                           (i) Ethyl magnesium chloride to propan-1-ol

                           (ii) Methyl magnesium bromide to 2-methylpropan-2-ol

                                  Or

(a)    Write mechanism of hydration of ethane.

(b)    How will you convert eumane to phenol.

(c)     How will you synthesized the following from appropriate alkene?

 

30.                (a)  Why is actinoid contraction is   greater from element to element than  lanthanoid contraction?

(b)   Complete the reaction

                            Cr2O7­­--+I-             

(c)    Calculate spin only magnetic moment of M++ (Z=24).

(d)   Explain why Ce4+ is strong oxidizing agent?

 

                                              Or

(a)    What is lanthanoid contraction and their consequences

(b)   Givereason why d1 Configuration is very unstable in ions

(c)     Why is highest oxidation state ofa metal exhibited in its oxide or fluoride only?

(d)    Why transition elements act as good catalyst.

   

 

 

                                                                                                             

 

 

 

SAMPLE PAPER-2013

CLASS-XII

Subject:- CHEMISTRY

 

TIME-3HRS                                                                                                                 M.M-70

 

 INSTRUCTIONS-

1. Q.-1 TO 8, CARRY ONE MARK,  

2. Q- 9     TO  18  CARRY TWO MARKS. 

3. Q- 19   TO   27  CARRY THREE MARKS.                             

4. Q- 28   TO  30  CARRY FIVE MARKS

 

1.Define Reverse Osmosis and its one application?

    2.What is the coagulation process?                            

3. What is the role of NaCN in the extraction of silver from a silver ore.

4.Give an example of coordination isomer.

5.Write IUPAC name of  CH3- C(CH3) = C(Br) – CH2OH

6. Draw structure of  4-tert.butyl-3-iodoheptane 

7. Why Primary amines have higher  boiling point than tertiary amines ?

8. Describe the  Primary structure  of protein?

9. Aluminium  has cubic close pack structure.  Its metallic radius is 125 pm. What is the length of  the side of unit cell  ?

10.How are the density and conductivity of crystals are affected  by Schottky defect and Frenkel Defect.?  

11. 45 gm ethylene Glycol (C2H6O2) is mixed with 600 gm of water. Calculate the freezing point depression and freezing point of the solution. Kf = 1.86 K Kg Mole -1

12. Find boiling point of solution containing 0.52 g of glucose dissolved in 80.2 g water. Kb=0.52kkg/m.

13. The rate constant for a first order reaction is 60 sec-1. How much time will it take to reduce the initial concentrations of the reactant to its 1/16 th value?

14.How  Zn is extracted from Zinc blende. Write reactions of extraction?

15. (a) Bond angle in PH4+ is higher than in PH3, Why?

(b) Why higher concentration of  O3 are explosives?

 

16. Explain (i) Crystal field splitting in an octahedral field (ii)Denticty of a ligand.

17. How would convert ethanol to ethene  ? Write mechanism?

18.(i) Why C-X bond in haloarene is shorter and stronger?

(ii) What are ambident nucleophiles

19. A reaction is of first order in reactant A and second order in reactant B. How is the rate of this   reaction  affected,when (i) concentration of B is increased three times 

(ii) Concentration of A and B  is doubled.?

20. Write three special features of  chemisorption  which are not found in physisorption?

21.  Assign reason- (i) Sulphur vapour is paramagnetic .

     (ii) SF6 is much less reactive than  SF4

    (iii) Of the noble gases only xenon is known to form well established compounds .

22. Explain (i) Fluorine does not exhibit any positive oxidation states.

     (ii) NO2 dimerise to form N2O4.?

     (iii) OF6 is not known .

23. Name the reagents used in conversion of  (i) A primary alcohol to an aldehyde

      (ii) Butan-2-one to Butan-2-ol        (iii)   Phenol to 2,4,6-tribromophenol

24. Complete the following- (i)C6H5N2Cl   + C6H5NH2 → …

     (ii)  C6H5N2Cl   +    CH3CH2OH  →…….    (iii)   R- NH2  +  CHCl3 + KOH →……..

25.What are the essential and non-essential amino acids in human food? Give one example of each type.?

26. Identify the four groups into which the polymers are classified on the basis of the magnitude of intermolecular forces present in them .To which group do polythene and bakelite belong ?

27. Explain- (i) Antibiotics (ii) Antiseptic (iii) Analgesics

28.(a) State Henry’s law about the gas phase pressure and solubility of a gas in a solvent and mention two of  its applications

(b) A copper –silver cell is set up. The copper ion concentration in it is 0.10 M . The concentration of  silver ion is not known. The cell potential measured is 0.422 V. determine the concentration of silver  ion in the cell.  E0Cu2+/Cu = 0.34 V and E0 Ag+/Ag = 0.80 V

29. (a)Complete the following (i) MnO4  (aq) +  C2O4 -2 + H+  →……………

.(ii) Cu++  +  I-1→……..

 (b)Explain about transition and inner transition elements-

      (i)There is in general increase in density of elements from Ti to Cu .

     (ii)There occurs much more frequent metal –metal bonding in compounds of heavy  

    transition  elements in 3d- series.   

    (iii)The members in the actinoid series exhibit large number of oxidation states than the  

         lanthanoids

30.  (a)   How would you account        

      (i) Aldehydes are more reactive than ketones towards nucleophiles.

(ii) The boiling points of aldehydes are ketones are lower than that of the corresponding acids.

(iii)The aldehydes and ketones undergo a number of addition reactions

      (b) Give chemical test to distinguish   (i) Acetaldehydes and Benzaldehydes

      (ii) Propanone and propanal 

 

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