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1 [P.T.O. ¸Öê»Ö ®ÖÓ . Roll No. ¸ÃÖÖµÖ®Ö ×¾Ö–ÖÖ®Ö (ÃÖî¨Ö×®ŸÖÛ ) CHEMISTRY (Theory) ×®Ö¬ÖÖÔ ×¸ŸÖ ÃÖ´ÖµÖ : 3 ‘Ö Ó™ê ] [ †×¬ÖÛ ŸÖ´Ö †ÓÛ : 70 Time allowed : 3 hours ] [ Maximum Marks : 70 ÃÖÖ´ÖÖ®µÖ ×®Ö¤ì¿Ö : (i) ÃÖ³Öß ¯Ö Ï ¿®Ö †×®Ö¾ÖÖµÖ Ô Æï … (ii) ¯ÖÏ ¿®Ö-ÃÖ ÓܵÖÖ 1 ÃÖ ê 5 ŸÖÛ †×ŸÖ »Ö‘Ö ã -ˆ¢Ö¸ßµÖ ¯Ö Ï ¿®Ö Æï †Öî ¸ ¯ÖÏ ŸµÖ ê Û ¯Ö Ï ¿®Ö Ûê ×»Ö‹ 1 ÓÛ Æî … (iii) ¯ÖÏ ¿®Ö-ÃÖ ÓܵÖÖ 6 ÃÖ ê 10 ŸÖÛ »Ö‘Ö ã -ˆ¢Ö¸ßµÖ ¯Ö Ï ¿®Ö Æï †Ö î ¸ ¯ÖÏ ŸµÖ ê Û ¯Ö Ï¿®Ö Ûê ×»Ö‹ 2 ÓÛ Æï … (iv) ¯ÖÏ ¿®Ö-ÃÖ ÓܵÖÖ 11 ÃÖ ê 22 ŸÖÛ ³Öß »Ö‘Öã -ˆ¢Ö¸ßµÖ ¯Ö Ï ¿®Ö Æï †Öî ¸ ¯Ö Ï ŸµÖê Û ¯ÖÏ ¿®Ö Ûê ×»Ö‹ 3 ÓÛ Æï … (v) ¯ÖÏ ¿®Ö-ÃÖ ÓܵÖÖ 23 ´Ö æ »µÖÖ¬ÖÖ׸ŸÖ ¯Ö Ï ¿®Ö Æî †Öî ¸ ‡ÃÖÛê ×»Ö‹ 4 ÓÛ Æï … ¿®Ö-ÃÖ ÓܵÖÖ 24 ÃÖ ê 26 ŸÖÛ ¤ß‘Ö Ô -ˆ¢Ö¸ßµÖ ¯ÖÏ ¿®Ö Æï †Ö î ¸ ¯ÖÏ ŸµÖ ê Û ¯ÖÏ ¿®Ö Ûê ×»Ö‹ 5 ÓÛ Æï … µÖפ †Ö¾Ö¿µÖÛ ŸÖÖ ÆÖ ê , ŸÖÖê »ÖÖòÝÖ ™ê²Ö»ÖÖë Û Ö ¯ÖÏ µÖÖ ê ÝÖ Û ¸ë … Ûî »ÖÛã »Öê ™¸Öë Ûê ˆ¯ÖµÖÖ ê ÝÖ Û ß †®Öã ´Ö×ŸÖ ®ÖÆà Æî … Series : SSO/C 56/3 Ûé ¯ÖµÖÖ •ÖÖ Ñ“Ö Û ¸ »Öë ×Û ‡ÃÖ ¯Ö Ï¿®Ö-¯Ö¡Ö ´Ö ë ´ÖãצŸÖ ¯Ö éš 12 Æï … ¯ÖÏ¿®Ö-¯Ö¡Ö ´Öë ¤Ö×Æ®Ö ê ÆÖ£Ö Û ß †Ö ê¸ ×¤‹ ÝÖ‹ Û Ö ê› ®Ö´²Ö¸ Û Ö ê ”Ö¡Ö ˆ¢Ö¸-¯Ö ã×ßÖÛ Ö Ûê ´ÖãÜÖ-¯Ö éš ¯Ö¸ ×»ÖÜÖ ë Ûé ¯ÖµÖÖ •ÖÖ Ñ“Ö Û ¸ »Öë ×Û ‡ÃÖ ¯Ö Ï¿®Ö-¯Ö¡Ö ´Ö ë 26 ¯Ö Ï¿®Ö Æï … Ûé ¯ÖµÖÖ ¯ÖÏ¿®Ö Û Ö ˆ¢Ö¸ ×»ÖÜÖ®ÖÖ ¿Öãº Û ¸®Öê ÃÖê ¯ÖÆ»Öê , ¯ÖÏ¿®Ö Û Ö ÛÎ ´ÖÖÓÛ †¾Ö¿µÖ ×»ÖÜÖë ‡ÃÖ ¯Ö Ï¿®Ö-¯Ö¡Ö Û Ö ê ¯ÖœÌ®Öê Ûê ×»Ö‹ 15 ×´Ö®Ö™ Û Ö ÃÖ´ÖµÖ ×¤µÖÖ ÝÖµÖÖ Æî … ¯ÖÏ¿®Ö-¯Ö¡Ö Û Ö ×¾ÖŸÖ¸ÞÖ ¯Öæ¾ÖÖ ÔÆ訅 ´Öë 10.15 ²Ö•Öê ×Û µÖÖ •ÖÖµÖ êÝÖÖ … 10.15 ²Ö•Öê ÃÖê 10.30 ²Ö•Ö ê ŸÖÛ ”Ö¡Ö Ûê ¾Ö»Ö ¯ÖÏ¿®Ö-¯Ö¡Ö Û Ö ê ¯ÖœÌëÝÖê †Öî¸ ‡ÃÖ †¾Ö×¬Ö Ûê ¤Öî¸Ö®Ö ¾Öê ˆ¢Ö¸-¯Ö ã×ßÖÛ Ö ¯Ö¸ Û Ö ê‡Ô ˆ¢Ö¸ ®ÖÆà ×»ÖÜÖëÝÖê Please check that this question paper contains 12 printed pages. Code number given on the right hand side of the question paper should be written on the title page of the answer-book by the candidate. Please check that this question paper contains 26 questions. Please write down the Serial Number of the question before attempting it. 15 minutes time has been allotted to read this question paper. The question paper will be distributed at 10.15 a.m. From 10.15 a.m. to 10.30 a.m., the students will read the question paper only and will not write any answer on the answer-book during this period. Û Öê› ®ÖÓ . Code No. Ł ¯Ö¸ßõÖÖ£Öá Û Ö ê› Û Ö ê ˆ¢Ö¸ -¯Ö ã×ßÖÛ Ö Ûê ´ÖãÜÖ-¯Ö éš ¯Ö¸ †¾Ö¿µÖ ×»ÖÜÖ ë Candidates must write the Code on the title page of the answer-book. SET – 3

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Chemistry Past Papers

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  • 56/3 1 [P.T.O.

    .

    Roll No.

    ( ) CHEMISTRY (Theory)

    : 3 ] [ : 70 Time allowed : 3 hours ] [ Maximum Marks : 70

    ::::

    (i) (ii) - 1 5 - 1 (iii) - 6 10 - 2 (iv) - 11 22 - 3 (v) - 23 4 (vi) - 24 26 - 5 (vii) ,

    Series : SSO/C 56/3

    - 12 - - - - 26 , - 15 - 10.15

    10.15 10.30 - -

    Please check that this question paper contains 12 printed pages. Code number given on the right hand side of the question paper should be written on the

    title page of the answer-book by the candidate. Please check that this question paper contains 26 questions. Please write down the Serial Number of the question before attempting it. 15 minutes time has been allotted to read this question paper. The question paper will be

    distributed at 10.15 a.m. From 10.15 a.m. to 10.30 a.m., the students will read the question paper only and will not write any answer on the answer-book during this period.

    . Code No.

    - - Candidates must write the Code on the title page of the answer-book.

    SET 3

  • 56/3 2

    General Instructions : (i) All questions are compulsory. (ii) Question number 1 to 5 are very short answer questions and carry 1 mark each. (iii) Question number 6 to 10 are short answer questions and carry 2 marks each. (iv) Question number 11 to 22 are also short answer questions and carry 3 marks each. (v) Question number 23 is a value based question and carry 4 marks. (vi) Question number 24 to 26 are long answer questions and carry 5 marks each. (vii) Use log tables, if necessary. Use of calculators is not allowed.

    1. ?

    What is meant by chelate effect ?

    2. (IUPAC) :

    CH3 CH2 CHO

    Write the IUPAC name of the following :

    CH3 CH2 CHO

    3. :

    , p- p-

    Arrange the following in increasing order of basic strength :

    Aniline, p-Nitroaniline and p-Toluidine

    4. AgCl ? What type of stoichiometric defect is shown by AgCl ?

    5. ?

    What are emulsions ? Give an example.

  • 56/3 3 [P.T.O.

    6.

    ?

    (i) (ii) H2S

    Describe the preparation of potassium permanganate. How does the acidified

    permanganate solution react with oxalic acid ? Write the ionic equations for the

    reactions.

    OR

    Describe the oxidising action of potassium dichromate and write the ionic equations

    for its reaction with (i) an iodide (ii) H2S.

    7.

    Write the mechanism of acid dehydration of ethanol to yield ethene.

    8. :

    (i) (x)

    (ii) (m)

    Define the following terms :

    (i) Mole fraction (x)

    (ii) Molality of a solution (m)

  • 56/3 4

    9.

    mol L1

    Write units of rate constants for zero order and for the second order reactions if the

    concentration is expressed in mol L1 and time in second.

    10. :

    (i)

    (ii) NF3 NCl3

    Explain the following :

    (i) Nitrogen is much less reactive than phosphorus.

    (ii) NF3 is an exothermic compound but NCl3 is an endothermic compound.

    11. ?

    What is meant by disproportionation ? Give one example of disproportionation reaction in aqueous solutions.

    12. IUPAC :

    (i) [Co(NH3)6]Cl3

    (ii) [NiCl4]2

    (iii) K3[Fe(CN)6]

    Write the IUPAC name of the following :

    (i) [Co(NH3)6]Cl3

    (ii) [NiCl4]2

    (iii) K3[Fe(CN)6]

  • 56/3 5 [P.T.O.

    13. (IUPAC) :

    (i) CH3 CH | Br

    CH2 CH3

    (ii)

    Br

    Br

    (iii) CH2 = CH CH2 Cl

    Give the IUPAC names of the following compounds :

    (i) CH3 CH | Br

    CH2 CH3

    (ii)

    Br

    Br

    (iii) CH2 = CH CH2 Cl

    14. ?

    (i)

    (ii) -1-

    (iii) -2-

    How are the following conversions carried out ?

    (i) Benzyl chloride to Benzyl alcohol

    (ii) Ethyl magnesium chloride to Propan-1-ol

    (iii) Propene to Propan-2-ol

  • 56/3 6

    15. :

    (i) CH3 CH2OH PCl5

    ?

    (ii)

    OH

    + CH3 Cl anhyd. AlCl3

    ?

    (iii) CH3 Cl + CH3CH2 ONa ?

    Write the major product in the following equations :

    (i) CH3 CH2OH PCl5

    ?

    (ii)

    OH

    + CH3 Cl anhyd. AlCl3

    ?

    (iii) CH3 Cl + CH3CH2 ONa ?

    16. :

    (i)

    (ii)

    (iii)

    Define the following as related to proteins :

    (i) Peptide linkage

    (ii) Primary structure (iii) Denaturation

    17.

    Explain the term copolymerization and give two examples of copolymerization.

  • 56/3 7 [P.T.O.

    18. fcc 4.077 108 cm ,

    (r)

    Silver crystallises in fcc lattice. If edge length of the unit cell is 4.077 108 cm, then

    calculate the radius of silver atom.

    19. - (M.W. 342) 5 ( ) X 0.877% X

    A 5 percent solution (by mass) of cane-sugar (M.W. 342) is isotonic with 0.877% solution of substance X. Find the molecular weight of X.

    20. 60 s1 1/10

    ?

    The rate constant for a first order reaction is 60 s1. How much time will it take to

    reduce the initial concentration of the reactant to its 1/10th value ?

    21. :

    (i)

    (ii)

    (iii)

    Describe the following processes :

    (i) Dialysis

    (ii) Electrophoresis

    (iii) Tyndall effect

  • 56/3 8

    22. :

    (i) ?

    (ii)

    (iii) ?

    Answer the following :

    (i) What is the role of cryolite in the metallurgy of aluminium ? (ii) Differentiate between roasting and calcination. (iii) What is meant by the term chromatography ? OR

    Write the reactions taking place in different zones of the blast furnace to obtain Iron.

    23.

    ,

    (i)

    (ii) ?

    (iii) ?

    Neeraj went to the departmental store to purchase groceries. On one of the shelves he noticed sugar free tablets. He decided to buy them for his grandfather who was a diabetic. There were three types of sugar free tablets. He decided to buy sucrolose which was good for his grandfathers health.

    (i) Name another sugar free tablet which Neeraj did not purchase. (ii) Was it right to purchase such medicines without doctors prescription ? (iii) What quality of Neeraj is reflected above ?

  • 56/3 9 [P.T.O.

    24. (a) :

    (i) p-

    (ii) 4--3--2-

    (b) :

    (i)

    (ii)

    (iii)

    (a) :

    (i)

    (ii) CH3CHO

    (b) ?

    (i) CH3 CH3

    (ii) CH3 CH | OH

    CH2 CHO

    (iii) CH3CH2OH

    (a) Draw the structures of the following :

    (i) p-Methylbenzaldehyde

    (ii) 4-Methylpent-3-en-2-one

    (b) Give chemical tests to distinguish between the following pairs of compounds :

    (i) Benzoic acid and Ethyl benzoate.

    (ii) Benzaldehyde and Acetophenone.

    (iii) Phenol and Benzoic acid.

    OR

  • 56/3 10

    (a) Draw the structures of the following derivatives :

    (i) Propanone oxime

    (ii) Semicarbazone of CH3CHO

    (b) How will you convert ethanal into the following compounds ? Give the chemical equations involved.

    (i) CH3 CH3

    (ii) CH3 CH | OH

    CH2 CHO

    (iii) CH3CH2OH

    25. (a) 16 15 ?

    (b)

    (i) H2SO4 CaF2 ?

    (ii) ?

    (iii) Ca(OH)2 ?

    (a) :

    (i) BrF3

    (ii) XeO3

    (b) :

    (i) PH3 NH3 ?

    (ii) ?

    (iii) XeOF4

  • 56/3 11 [P.T.O.

    (a) Elements of Gr. 16 generally show lower value of first ionization enthalpy compared to the corresponding periods of Gr. 15. Why ?

    (b) What happens when

    (i) concentrated H2SO4 is added to CaF2 ?

    (ii) sulphur dioxide reacts with chlorine in the presence of charcoal ?

    (iii) ammonium chloride is treated with Ca(OH)2 ?

    OR

    (a) Draw the structure of the following :

    (i) BrF3

    (ii) XeO3

    (b) Answer the following :

    (i) Why is NH3 more basic than PH3 ?

    (ii) Why are halogens strong oxidising agents ?

    (iii) Draw the structure of XeOF4.

    26. rG e.m.f.(E) 25 C :

    Zn(s) | Zn2+(aq) || Sn2+(aq) | Sn(s) : E

    Zn2+/Zn= 0.76 V; E

    Sn2+/Sn= 0.14 V

    F = 96500 C mol1

    (a) -

  • 56/3 12

    (b) :

    Fe2+(aq) + Ag+(aq) Fe3+(aq) + Ag(s)

    rG

    (EAg+/Ag

    = 0.80 V; EFe3+/Fe2+

    = 0.77 V)

    Calculate rG and e.m.f. (E) that can be obtained from the following cell under the standard conditions at 25 C :

    Zn(s) | Zn2+(aq) || Sn2+(aq) | Sn(s)

    Given : EZn2+/Zn

    = 0.76 V; ESn2+/Sn

    = 0.14 V

    and F = 96500 C mol1.

    OR

    (a) Define conductivity and molar conductivity for the solution of an electrolyte. Discuss their variation with concentration.

    (b) Calculate the standard cell potential of the galvanic cell in which the following reaction takes place :

    Fe2+(aq) + Ag+(aq) Fe3+(aq) + Ag(s)

    Calculate the rG and equilibrium constant of the reaction also.

    (EAg+/Ag

    = 0.80 V; EFe3+/Fe2+

    = 0.77 V)

    ____________

  • 1

    Qu

    es. Value points Marks

    1 Formation of stable complex by polydentate ligand. 1

    2 Propanal 1

    3 p-Nitroaniline < Aniline < p-Toluidine 1

    4 Frenkel defect 1

    5 Emulsions are liquid liquid colloidal systems. For example milk, cream (or any other one correct example)

    +

    6 Potassium permanganate is prepared by fusion of MnO2 with an alkali metal hydroxide and an

    oxidising agent like KNO3. This produces the dark green K2MnO4 which disproportionates in a

    neutral or acidic solution to give permanganate.

    Oxalate ion or oxalic acid is oxidised at 333 K:

    OR

    1

    1

    6 i)

    ii)

    1

    1

    7

    1

    CHEMISTRY MARKING SCHEME

    SET -56/3

    Compt. July, 2015

  • 2

    8 i)

    ii) Molality (m) is defined as the number of moles of the solute per kilogram (kg) of the

    solvent. Or

    1

    1

    9 Zero order : mol L-1

    s-1

    Second order : L mol-1

    s-1

    1

    1

    10 i) Due to high bond dissociation enthalpy of N N ii) Due to low bond dissociation enthalpy of F2 than Cl2 and strong bond formation

    between N and F

    1

    1

    11 Disproportionation : The reaction in which an element undergoes self-oxidation and self-

    reduction simultaneously. For example

    2Cu+ (aq) Cu

    2+ (aq) + Cu(s)

    (Or any other correct equation)

    1

    1

    12 i) Hexaamminecobalt(III) chloride

    ii) Tetrachlorido nickelate(II)

    iii) Potassium hexacyanoferrate(III)

    1

    1

    1

    13 i) 2-bromobutane

    ii) 1, 3-dibromobenzene

    iii) 3-choloropropene

    1

    1

    1

    14

    i)

    ii)

    1

    1

    1

    15

    i)

    1

  • 3

    ii)

    iii)

    1

    1

    16 i) Peptide linkage in proteins, -amino acids are connected to each other by peptide bond or peptide linkage (-CONH- bond).

    ii) Primary structure - each polypeptide in a protein molecule having amino acids which

    are linked with each other in a specific sequence.

    iii) Denaturation - When a protein is subjected to physical change like change in

    temperature or chemical change like change in pH, protein loses its biological activity.

    1

    1

    1

    17 Copolymerisation is a polymerisation reaction in which a mixture of more than one monomeric

    species is allowed to polymerise and form a copolymer.

    (or any other correct example)

    1

    1

    1

    18 r =

    r=

    r = 1.44 x cm

    1

    1

    1

    19 cane sugar = X

    Therefore, ccane sugar = cX (where c is molar concentration)

    =

    =

    MX =

    gmol

    -1

    MX = 59.9 or 60 gmol-1

    1

    1

    1

    20 k=

    log

    1

  • 4

    60 s-1

    =

    log

    t=

    log 10

    t=

    s

    t= 0.0384 s

    1

    1 21 i) It is a process of removing the dissolved substance from a colloidal solution by means

    of diffusion through a semi - permeable membrane.

    ii) The movement of colloidal particles under an applied electric potential towards

    oppositely charged electrode is called electrophoresis.

    iii) Colloidal particles scatter light in all directions in space. This scattering of light

    illuminates the path of beam in the colloidal dispersion.

    1

    1

    1 22 i) It lowers the melting point of alumina / acts as a solvent.

    ii)

    Roasting Calcination

    Ore is heated in a regular supply of air Heating in a limited supply or

    absence of air.

    (Or with equation)

    iii) It is a process of separation of different components of a mixture which are differently adsorbed on a suitable adsorbent.

    OR

    1

    1

    1

    22

    (any 6 correct equations)

    6 x

    = 3

    23 i) Aspartame, Saccharin (any one) ii) No iii) Social concern, empathy, concern, social awareness (any 2 )

    1

    1

    2 24 a) i)

    ii)

    b) i)Add NaHCO3, benzoic acid will give brisk effervescence of CO2 whereas ethylbenzoate

    1

    1

  • 5

    will not.

    ii)Add NaOH and I2, acetophonone forms yellow ppt of iodoform on heating whereas

    benzaldehyde will not.

    iii)Add neutral FeCl3, phenol gives violet colouration whereas benzoic acid does not. (or any other correct test)

    OR

    1

    1

    1

    24 a) i)

    ii)

    b) i)

    ii)

    iii)

    1

    1

    1

    1

    1

    25 a) Due to relatively stable half filled p-orbitals of group 15 elements

    b) i) CaF2 + H2SO4 CaSO4 + 2HF

    ii)

    iii)

    OR

    2

    1

    1

    1

    25

    a) i)

    1

  • 6

    ii)

    b) i)Due to small size of nitrogen, the lone pair of electron on nitrogen is localized/ easily

    available for donation.

    ii)Because they need only one electron to attain stable/noble gas configuration.

    iii)

    1

    1

    1

    1

    26 E0cell = E

    0Sn2+ / Sn - E

    0Zn2+ / Zn

    = - 0.14V (- 0.76V) = 0.62V

    rG0 = -n F E

    0cell

    = - 2 x 96500 C mol-1

    x 0.62 V

    = - 119660 J mol-1

    Ecell = E0

    cell -

    log

    Ecell = 0.62 -

    log

    OR

    1

    1

    1

    1

    1

    26 a) The conductivity of a solution at any given concentration is the conductance of one unit

    volume of solution kept between two platinum electrodes with unit area of cross section

    and at a distance of unit length.

    Molar conductivity of a solution at a given concentration is the conductance of the volume

    V of solution containing one mole of electrolyte kept between two electrodes with area of

    cross section A and distance of unit length.

    Molar conductivity increases with decrease in concentration.

    b)E0cell = E

    0C - E

    0A

    = 0.80V 0.77V = 0.03V

    rG0 = -n F E

    0cell

    = - 1 x 96500 C mol-1

    x 0.03 V

    = - 2895 J mol-1

    Log Kc=

    1

    1

  • 7

    Dr. Sangeeta Bhatia Sh. S.K. Munjal Sh. D.A. Mishra

    Ms. Garima Bhutani

    Log Kc=

    Log Kc= 0.508

  • 56/1/3 1 [P.T.O.

    .

    Roll No.

    ( ) CHEMISTRY (Theory)

    : 3 ] [ : 70 Time allowed : 3 hours ] [ Maximum Marks : 70

    ::::

    (i) (ii) - 1 5 - 1 (iii) - 6 10 - 2 (iv) - 11 22 - 3 (v) - 23 4 (vi) - 24 26 - 5 (vii)

    Series : SSO/1/C 56/1/3

    - 11 - - - - 26 , - 15 - 10.15

    10.15 10.30 - -

    Please check that this question paper contains 11 printed pages. Code number given on the right hand side of the question paper should be written on the

    title page of the answer-book by the candidate. Please check that this question paper contains 26 questions. Please write down the Serial Number of the question before attempting it. 15 minutes time has been allotted to read this question paper. The question paper will be

    distributed at 10.15 a.m. From 10.15 a.m. to 10.30 a.m., the students will read the question paper only and will not write any answer on the answer-book during this period.

    . Code No.

    - - Candidates must write the Code on the title page of the answer-book.

    SET 3

  • 56/1/3 2

    General Instructions : (i) All questions are compulsory. (ii) Q. No. 1 to 5 are very short answer questions and carry 1 mark each. (iii) Q. No. 6 to 10 are short answer questions and carry 2 marks each. (iv) Q. No. 11 to 22 are also short answer questions and carry 3 marks each. (v) Q. No. 23 is a value based question and carry 4 marks. (vi) Q. No. 24 to 26 are long answer questions and carry 5 marks each. (vii) Use log tables if necessary, use of calculator is not allowed.

    1. [Ni(NH3)6]Cl2 (IUPAC)

    What is the IUPAC name of the complex [Ni(NH3)6]Cl2 ?

    2.

    3-

    Draw the structure of 3-methylpentanal.

    3. :

    C6H5N2Cl + H3PO2 + H2O - - -

    Complete the following reaction equation :

    C6H5N2Cl + H3PO2 + H2O - - -

    4. : (z) ? What is the no. of atoms per unit cell (z) in a body-centred cubic structure ?

    5.

    In reference to surface chemistry, define dialysis.

  • 56/1/3 3 [P.T.O.

    6. :-

    CH3CH2OH H+

    443 K

    CH2 = CH2 + H2O

    Explain the mechanism of dehydration steps of ethanol :-

    CH3CH2OH H+

    443 K

    CH2 = CH2 + H2O

    7. ? Define osmotic pressure of a solution. How is the osmotic pressure related to the concentration of a solute in a solution ?

    8. : (i) (t) (ii) (k) Define the following terms : (i) Half-life of a reaction (t) (ii) Rate constant (k)

    9. : (i) H2SO4 (ii) XeF2 Draw the structures of the following : (i) H2SO4 (ii) XeF2

    10. ?

    :

    (i) (ii) What is meant by disproportionation ? Give an example of a disproportionation

    reaction in aqueous solution. OR

    Suggest reasons for the following features of transition metal chemistry : (i) The transition metals and their compounds are usually paramagnetic. (ii) The transition metals exhibit variable oxidation states.

  • 56/1/3 4

    11. ?

    (i) -2- (ii) (iii) p- How are the following conversions carried out ?

    (i) Propene to propane-2-ol (ii) Benzyl chloride to Benzyl alcohol (iii) Anisole to p-Bromoanisole

    12. A B Br2 KOH C C C6H7N A, B C (IUPAC)

    An aromatic compound A on treatment with aqueous ammonia and heating forms compound B which on heating with Br2 and KOH forms a compound C of molecular formula C6H7N. Write the structures and IUPAC names of compounds A, B and C.

    13. ? How are vitamins classified ? Name the vitamin responsible for the coagulation of blood.

    14. :

    (i) -S (ii) (iii) Write the names and structures of the monomers of the following polymers :

    (i) Buna-S (ii) Neoprene (iii) Teflon

  • 56/1/3 5 [P.T.O.

    15. : (i) (ii) (iii) F- Define the following : (i) Schottky defect (ii) Frenkel defect (iii) F-centre

    16. (C2H4O2) 45 g 600 g

    (i) (ii) ( : Kf = 1.86 K kg mol1)

    45 g of ethylene glycol (C2H4O2) is mixed with 600 g of water. Calculate (i) the freezing point depression and (ii) the freezing point of the solution (Given : Kf of water = 1.86 K kg mol1)

    17. 500 K 700 K : 0.02 s1 0.07 s1

    , Ea (R = 8.314 J K1 mol1)

    The rate constants of a reaction at 500 K and 700 K are 0.02 s1 and 0.07 s1 respectively. Calculate the value of activation energy, Ea. (R = 8.314 J K1 mol1)

    18. : (i) (ii) (iii) - ( ) Define the following terms : (i) Electrophoresis (ii) Adsorption (iii) Shape selective catalysis

  • 56/1/3 6

    19. :

    (i)

    (ii)

    (iii)

    (Pig) ?

    Outline the principles of refining of metals by the following methods :

    (i) Distillation (ii) Zone refining (iii) Electrolysis OR

    Write down the reactions taking place in different zones in the blast furnace during the extraction of iron. How is pig iron different from cast iron ?

    20. ? ?

    What is lanthanoid contraction ? What are the consequences of lanthanoid contraction ?

    21. :

    (i) [Co(NH3)5(NO2)]2+

    (ii) [Co(en)3]Cl3 (en = )

    (iii) [Pt(NH3)2Cl2]

    Indicate the types of isomerism exhibited by the following complexes :

    (i) [Co(NH3)5(NO2)]2+

    (ii) [Co(en)3]Cl3 (en = ethylene diamine)

    (iii) [Pt(NH3)2Cl2]

  • 56/1/3 7 [P.T.O.

    22. (IUPAC) : (i) CH3 CH |

    OH

    CH2 CH3

    (ii)

    (iii) CH3 CH3|

    C | CH3

    CH2 Cl

    Name the following according to IUPAC system : (i) CH3 CH |

    OH

    CH2 CH3

    (ii)

    (iii) CH3 CH3|

    C | CH3

    CH2 Cl

    23. - -

    (i) (ii) ? (iii) ? Ramesh went to a departmental store to purchase groceries. On one of shelves he

    noticed sugar-free tablets. He decided to buy them for his grandfather who was a diabetic. There were three types of sugar-free tablets. Ramesh decided to buy sucrolose which was good for his grandfathers health.

    (i) Name another sugar free tablet which Ramesh did not buy. (ii) Was it right to purchase such medicines without doctors prescription ? (iii) What quality of Ramesh is reflected above ?

  • 56/1/3 8

    24. (a) :

    (i)

    (ii) -

    (b) ?

    (i)

    (ii) m-

    (iii) 3-

    (a) :

    (i)

    (ii) (b) :

    (i) CH3 C | |O

    CH3 LiAlH4

    ?

    (ii)

    CHO

    HNO3 / H2SO4

    273 283 K ?

    (iii) CH3 COOH PCl5

    ?

    (a) Describe the following giving chemical equations : (i) De-carboxylation reaction (ii) Friedel-Crafts reaction (b) How will you bring about the following conversions ? (i) Benzoic acid to Benzaldehyde (ii) Benzene to m-Nitroacetophenone (iii) Ethanol to 3-Hydroxybutanal OR

  • 56/1/3 9 [P.T.O.

    (a) Describe the following actions : (i) Acetylation (ii) Aldol condensation (b) Write the main product in the following equations :

    (i) CH3 C | |O

    CH3 LiAlH4

    ?

    (ii)

    CHO

    HNO3 / H2SO4

    273 283 K ?

    (iii) CH3 COOH PCl5

    ?

    25. (a) : (i) Cu + HNO3()

    (ii) P4 + NaOH+ H2O

    (b) (i) R3P = O R3N = O ? (R = )

    (ii) ? (iii) ?

    (a) : (i) (ii) H2SO4

    (b) , ,

    (a) Complete the following chemical reaction equations :

    (i) Cu + HNO3(dilute)

    (ii) P4 + NaOH+ H2O

  • 56/1/3 10

    (b) (i) Why does R3P = O exist but R3N = O does not ? (R = alkyl group)

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

    (iii) Why are halogens coloured ?

    OR

    (a) Write balanced equations for the following reactions :

    (i) Chlorine reacts with dry slaked lime.

    (ii) Carbon reacts with concentrated H2SO4.

    (b) Describe the contact process for the manufacture of sulphuric acid with special reference to the reaction conditions, catalysts used and the yield in the process.

    26. (a) : (i) (^m)

    (ii) (iii)

    (b) : (i) (ii)

    (a) -

    (b) Ni(s) | Ni2+(aq) || Ag+(aq) | Ag(s) 25 C

    ?

    ENi2+/Ni= 0.25 V, EAg+/Ag= 0.80 V.

  • 56/1/3 11 [P.T.O.

    (a) Define the following terms : (i) Molar conductivity (^m)

    (ii) Secondary batteries (iii) Fuel cell (b) State the following laws : (i) Faraday first law of electrolysis (ii) Kohlrauschs law of independent migration of ions

    OR

    (a) Define the term degree of dissociation. Write an expression that relates the molar conductivity of a weak electrolyte to its degree of dissociation.

    (b) For the cell reaction Ni(s) | Ni2+(aq) || Ag+(aq) | Ag(s) Calculate the equilibrium constant at 25 C. How much maximum work would

    be obtained by operation of this cell ?

    ENi2+/Ni= 0.25 V and EAg+/Ag= 0.80 V.

    ___________

  • 56/1/3 12

  • 1

    Qu

    es. Value points Marks

    1 Hexaamninenickel (II) chloride 1

    2

    1

    3

    (where Ar is C6H5)

    1

    4 2 1

    5 It is a process of removing a dissolved substance from a colloidal solution by means of diffusion

    through a suitable membrane.

    1

    6

    1

    7 The external pressure which is applied on solution side to stop the flow of solvent across the

    semi-permeable membrane.

    The osmotic pressure is directly proportional to concentration of the solution. / = CRT

    1

    1

    8 The half-life of a reaction is the time in which the concentration of a reactant is reduced to one-

    half of its initial concentration.

    Rate constant is the rate of reaction when the concentration of the reactant is unity.

    1

    1

    CHEMISTRY MARKING SCHEME

    SET -56/1/3

    Compt. July, 2015

  • 2

    9

    i) ii)

    1+1

    10 Disproportionation : The reaction in which an element undergoes self-oxidation and self-

    reduction simultaneously. For example

    2Cu+ (aq) Cu

    2+ (aq) + Cu(s)

    (Or any other correct equation)

    OR

    1

    1

    10 i) Due to presence of unpaired electrons in d-orbitals. ii) Due to incomplete filling of d-orbitals.

    1

    1

    11 i)

    ii)

    iii)

    1

    1

    1

    12

    A Benzoic acid

    B Benzamide

    +

    +

  • 3

    C - Aniline

    +

    13 Fat soluble vitamin- Vitamin A, D

    Water soluble vitamin-Vitamin B,C

    Vitamin K

    +

    +

    1

    14 i)

    ii)

    iii)

    +

    +

    +

    15 i) The defect in which equal number of cations and anions are missing from the lattice. ii) Due to dislocation of smaller ion from its normal site to an interstitial site. iii) Anionic vacancies are occupied by unpaired electron.

    1

    1

    1

    16 i) Tf = Kf m

    Tf = Kf

    Tf =

    Tf =2.325K or 2.3250

    C

    ii) Tf0- Tf = 2.325

    0 C

    O0C - Tf = 2.325

    0 C

    Tf = - 2.3250

    C or 270.675 K

    1

    1

    17

    1

    1

    1

    18 i) The movement of colloidal particles under an applied electric potential towards oppositely charged electrode is called electrophoresis.

    ii) The accumulation of molecular species at the surface rather than in the bulk of a solid or liquid

    1

    1

  • 4

    is termed adsorption.

    iii) The catalytic reaction that depends upon the pore structure of the catalyst and the size of the

    reactant and product molecules is called shape-selective catalysis.

    1

    19 i) The impure metal is evaporated to obtain the pure metal as distillate. ii) This method is based on the principle that the impurities are more soluble in the melt than in

    the solid state of the metal.

    iii) The impure metal is made to act as anode. A strip of the same metal in pure form is used as cathode. They are put in a suitable electrolytic bath containing soluble salt of the same metal.

    The more basic metal remains in the solution and the less basic ones go to the anode mud.

    OR

    1

    1

    1

    19

    ( any four correct equations) Cast iron has lower carbon content (about 3%) than pig iron / cast iron is hard & brittle whereas pig iron is soft.

    x 4

    = 2

    1

    20 The steady decrease in atomic radii from La to Lu due to imperfect shielding of 4f orbital. Consequences i) Members of third transition series have almost identical radii as coresponding members

    of second transition series.

    ii) Difficulty in separation.

    1

    1+1

    21 a) Linkage isomerism b) Optical isomerism c) Cis - trans / Geometrical isomerism

    1

    1

    1

    22 a) Butan 2 ol b) 2 bromotoluene c) 2, 2-dimethylchlorpropane

    1

    1

    1

    23 i) Aspartame, Saccharin (any one) ii) No iii) Social concern, empathy, concern, social awareness (any 2 )

    1

    1

    2

    24 a) i) Carboxylic acids lose carbon dioxide to form hydrocarbons when their sodium salts are heated with sodalime (NaOH and CaO).

    ii) When the alkyl / acyl group is introduced at ortho and para positions by reaction

    with alkyl halide / acyl halide in the presence of anhydrous aluminium chloride (a Lewis

    acid) as catalyst.

    1

  • 5

    (Note : Award full marks if correct equation is given )

    b) i)

    ii)

    iii)

    (or any other correct method)

    OR

    1

    1

    1

    1

    24 a) i) When the acyl groups are introduced at ortho and para positions by reaction with acyl halide in the presence of anhydrous aluminium chloride (a Lewis acid) as catalyst.

    ii) Aldehydes and ketones having at least one -hydrogen undergo a reaction in the presence of dilute alkali as catalyst to form -hydroxy aldehydes (aldol) or hydroxy ketones (ketol), respectively.

    (Note : Award full marks if correct equation is given )

    b)i)

    1

    1

    1

  • 6

    ii)

    iii) CH3COCl

    1

    1

    25 a) i)

    ii)

    b) i) Due to absence of d-orbital, nitrogen cannot expand its valency beyond four. ii) Because of p p multiple bonding in dioxygen which is absent in sulphur. iii) Due to excitation of electron by absorption of radiation from visible region.

    OR

    1

    1

    1

    1

    1

    25 a) i)

    ii)

    b) It is manufactured by Contact Process which involves following steps:

    i) burning of sulphur or sulphide ores in air to generate SO2.

    ii) conversion of SO2 to SO3 by the reaction with oxygen in the presence of a catalyst (V2O5)

    iii) absorption of SO3 in H2SO4 to give Oleum (H2S2O7). The oleum obtained is diluted to give

    sulphuric acid

    Reaction condition pressure of 2 bar and temperature of 720 K Catalyst used is V2O5

    Yield 96 98% pure

    1

    1

    1

    1

    1

    26 a)i)Molar conductivity of a solution at a given concentration is the conductance of the volume V

    of solution containing one mole of electrolyte kept between two electrodes with area of cross

    section A and distance of unit length.

    ii) Secondary battery- can be recharged by passing current through it in opposite direction so that

    it can be used again.

    iii) Galvanic cells that are designed to convert the energy of combustion of fuels like hydrogen,

    methane, methanol, etc. directly into electrical energy are called fuel cells.

    b)i) The amount of chemical reaction which occurs at any electrode during electrolysis by a

    current is proportional to the quantity of electricity passed through the electrolyte (solution or

    melt).

    ii) Limiting molar conductivity of an electrolyte can be represented as the sum of the individual

    contributions of the anion and cation of the electrolyte.

    OR

    1

    1

    1

    1

    1

    26 a) Degree of dissociation is the extent to which electrolyte gets dissociated into its constituent

    ions.

    b) E

    0cell = E

    0Ag+ / Ag - E

    0Ni2+ / Ni

    = 0.80V 0.25V

    1

    1

  • 7

    Dr. Sangeeta Bhatia Sh. S.K. Munjal Sh. D.A. Mishra

    Ms. Garima Bhutani

    = 0.55V

    1og Kc =

    =

    log Kc = 18.644

    G0 = - nFE0cell = -2x96500 Cmol

    -1 x 0.55V

    = -106,150 Jmol-1

    Max.work =+106150 Jmol-1

    or 106.150k Jmol-1

    1

  • 56/2 1 [P.T.O.

    .

    Roll No.

    ( ) CHEMISTRY (Theory)

    : 3 ] [ : 70 Time allowed : 3 hours ] [ Maximum Marks : 70

    ::::

    (i) (ii) - 1 5 - 1 (iii) - 6 10 - 2 (iv) - 11 22 - 3 (v) - 23 4 (vi) - 24 26 - 5 (vii) ,

    Series : SSO/C 56/2

    - 12 - - - - 26 , - 15 - 10.15

    10.15 10.30 - -

    Please check that this question paper contains 12 printed pages. Code number given on the right hand side of the question paper should be written on the

    title page of the answer-book by the candidate. Please check that this question paper contains 26 questions. Please write down the Serial Number of the question before attempting it. 15 minutes time has been allotted to read this question paper. The question paper will be

    distributed at 10.15 a.m. From 10.15 a.m. to 10.30 a.m., the students will read the question paper only and will not write any answer on the answer-book during this period.

    . Code No.

    - - Candidates must write the Code on the title page of the answer-book.

    SET 2

  • 56/2 2

    General Instructions : (i) All questions are compulsory. (ii) Question number 1 to 5 are very short answer questions and carry 1 mark each. (iii) Question number 6 to 10 are short answer questions and carry 2 marks each. (iv) Question number 11 to 22 are also short answer questions and carry 3 marks each. (v) Question number 23 is a value based question and carry 4 marks. (vi) Question number 24 to 26 are long answer questions and carry 5 marks each. (vii) Use log tables, if necessary. Use of calculators is not allowed.

    1. ?

    What are emulsions ? Give an example.

    2. ?

    What is meant by chelate effect ?

    3. (IUPAC) :

    CH3 CH2 CHO

    Write the IUPAC name of the following :

    CH3 CH2 CHO

    4. :

    , p- p-

    Arrange the following in increasing order of basic strength :

    Aniline, p-Nitroaniline and p-Toluidine

    5. AgCl ?

    What type of stoichiometric defect is shown by AgCl ?

  • 56/2 3 [P.T.O.

    6. :

    (i) (ii) NF3 NCl3

    Explain the following :

    (i) Nitrogen is much less reactive than phosphorus. (ii) NF3 is an exothermic compound but NCl3 is an endothermic compound.

    7.

    ?

    (i) (ii) H2S

    Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with oxalic acid ? Write the ionic equations for the reactions.

    OR

    Describe the oxidising action of potassium dichromate and write the ionic equations for its reaction with (i) an iodide (ii) H2S.

    8.

    Write the mechanism of acid dehydration of ethanol to yield ethene.

    9. :

    (i) (x) (ii) (m) Define the following terms :

    (i) Mole fraction (x) (ii) Molality of a solution (m)

  • 56/2 4

    10. mol L1

    Write units of rate constants for zero order and for the second order reactions if the concentration is expressed in mol L1 and time in second.

    11. :

    (i) ? (ii) (iii) ?

    Answer the following :

    (i) What is the role of cryolite in the metallurgy of aluminium ? (ii) Differentiate between roasting and calcination. (iii) What is meant by the term chromatography ? OR Write the reactions taking place in different zones of the blast furnace to obtain Iron.

    12. ?

    What is meant by disproportionation ? Give one example of disproportionation reaction in aqueous solutions.

    13. IUPAC :

    (i) [Co(NH3)6]Cl3

    (ii) [NiCl4]2 (iii) K3[Fe(CN)6] Write the IUPAC name of the following :

    (i) [Co(NH3)6]Cl3

    (ii) [NiCl4]2 (iii) K3[Fe(CN)6]

  • 56/2 5 [P.T.O.

    14. (IUPAC) :

    (i) CH3 CH | Br

    CH2 CH3

    (ii)

    Br

    Br

    (iii) CH2 = CH CH2 Cl

    Give the IUPAC names of the following compounds :

    (i) CH3 CH | Br

    CH2 CH3

    (ii)

    Br

    Br

    (iii) CH2 = CH CH2 Cl

    15. ?

    (i)

    (ii) -1-

    (iii) -2-

    How are the following conversions carried out ?

    (i) Benzyl chloride to Benzyl alcohol

    (ii) Ethyl magnesium chloride to Propan-1-ol

    (iii) Propene to Propan-2-ol

  • 56/2 6

    16. :

    (i) CH3 CH2OH PCl5

    ?

    (ii)

    OH

    + CH3 Cl anhyd. AlCl3

    ?

    (iii) CH3 Cl + CH3CH2 ONa ?

    Write the major product in the following equations :

    (i) CH3 CH2OH PCl5

    ?

    (ii)

    OH

    + CH3 Cl anhyd. AlCl3

    ?

    (iii) CH3 Cl + CH3CH2 ONa ?

    17. :

    (i)

    (ii)

    (iii)

    Define the following as related to proteins :

    (i) Peptide linkage

    (ii) Primary structure (iii) Denaturation

    18.

    Explain the term copolymerization and give two examples of copolymerization.

  • 56/2 7 [P.T.O.

    19. fcc 4.077 108 cm ,

    (r)

    Silver crystallises in fcc lattice. If edge length of the unit cell is 4.077 108 cm, then

    calculate the radius of silver atom.

    20. - (M.W. 342) 5 ( ) X 0.877% X

    A 5 percent solution (by mass) of cane-sugar (M.W. 342) is isotonic with 0.877% solution of substance X. Find the molecular weight of X.

    21. 60 s1 1/10

    ?

    The rate constant for a first order reaction is 60 s1. How much time will it take to

    reduce the initial concentration of the reactant to its 1/10th value ?

    22. :

    (i)

    (ii)

    (iii)

    Describe the following processes :

    (i) Dialysis

    (ii) Electrophoresis

    (iii) Tyndall effect

  • 56/2 8

    23.

    ,

    (i)

    (ii) ?

    (iii) ?

    Neeraj went to the departmental store to purchase groceries. On one of the shelves he noticed sugar free tablets. He decided to buy them for his grandfather who was a

    diabetic. There were three types of sugar free tablets. He decided to buy sucrolose

    which was good for his grandfathers health.

    (i) Name another sugar free tablet which Neeraj did not purchase.

    (ii) Was it right to purchase such medicines without doctors prescription ?

    (iii) What quality of Neeraj is reflected above ?

    24. (a) 16 15 ?

    (b)

    (i) H2SO4 CaF2 ?

    (ii) ?

    (iii) Ca(OH)2 ?

  • 56/2 9 [P.T.O.

    (a) :

    (i) BrF3

    (ii) XeO3

    (b) :

    (i) PH3 NH3 ?

    (ii) ?

    (iii) XeOF4

    (a) Elements of Gr. 16 generally show lower value of first ionization enthalpy compared to the corresponding periods of Gr. 15. Why ?

    (b) What happens when

    (i) concentrated H2SO4 is added to CaF2 ?

    (ii) sulphur dioxide reacts with chlorine in the presence of charcoal ?

    (iii) ammonium chloride is treated with Ca(OH)2 ?

    OR

    (a) Draw the structure of the following :

    (i) BrF3

    (ii) XeO3

    (b) Answer the following :

    (i) Why is NH3 more basic than PH3 ?

    (ii) Why are halogens strong oxidising agents ?

    (iii) Draw the structure of XeOF4.

  • 56/2 10

    25. (a) :

    (i) p-

    (ii) 4--3--2-

    (b) :

    (i)

    (ii)

    (iii)

    (a) :

    (i)

    (ii) CH3CHO

    (b) ?

    (i) CH3 CH3

    (ii) CH3 CH | OH

    CH2 CHO

    (iii) CH3CH2OH

    (a) Draw the structures of the following :

    (i) p-Methylbenzaldehyde

    (ii) 4-Methylpent-3-en-2-one

    (b) Give chemical tests to distinguish between the following pairs of compounds :

    (i) Benzoic acid and Ethyl benzoate.

    (ii) Benzaldehyde and Acetophenone.

    (iii) Phenol and Benzoic acid.

    OR

  • 56/2 11 [P.T.O.

    (a) Draw the structures of the following derivatives :

    (i) Propanone oxime

    (ii) Semicarbazone of CH3CHO

    (b) How will you convert ethanal into the following compounds ? Give the chemical equations involved.

    (i) CH3 CH3

    (ii) CH3 CH | OH

    CH2 CHO

    (iii) CH3CH2OH

    26. rG e.m.f.(E) 25 C :

    Zn(s) | Zn2+(aq) || Sn2+(aq) | Sn(s)

    : EZn2+/Zn

    = 0.76 V; ESn2+/Sn

    = 0.14 V

    F = 96500 C mol1

    (a) -

    (b) :

    Fe2+(aq) + Ag+(aq) Fe3+(aq) + Ag(s)

    rG

    (EAg+/Ag

    = 0.80 V; EFe3+/Fe2+

    = 0.77 V)

  • 56/2 12

    Calculate rG and e.m.f. (E) that can be obtained from the following cell under the

    standard conditions at 25 C :

    Zn(s) | Zn2+(aq) || Sn2+(aq) | Sn(s)

    Given : EZn2+/Zn

    = 0.76 V; ESn2+/Sn

    = 0.14 V

    and F = 96500 C mol1.

    OR

    (a) Define conductivity and molar conductivity for the solution of an electrolyte. Discuss their variation with concentration.

    (b) Calculate the standard cell potential of the galvanic cell in which the following reaction takes place :

    Fe2+(aq) + Ag+(aq) Fe3+(aq) + Ag(s)

    Calculate the rG and equilibrium constant of the reaction also.

    (EAg+/Ag

    = 0.80 V; EFe3+/Fe2+

    = 0.77 V)

    ____________

  • 1

    Qu

    es. Value points Marks

    1 Emulsions are liquid liquid colloidal systems. For example milk, cream (or any other one correct example)

    +

    2 Formation of stable complex by polydentate ligand. 1

    3 Propanal 1

    4 p-Nitroaniline < Aniline < p-Toluidine 1

    5 Frenkel defect 1

    6 i) Due to high bond dissociation enthalpy of N N ii) Due to low bond dissociation enthalpy of F2 than Cl2 and strong bond formation

    between N and F

    1

    1

    7 Potassium permanganate is prepared by fusion of MnO2 with an alkali metal hydroxide and an

    oxidising agent like KNO3. This produces the dark green K2MnO4 which disproportionates in a

    neutral or acidic solution to give permanganate.

    Oxalate ion or oxalic acid is oxidised at 333 K:

    OR

    1

    1

    7 i)

    ii)

    1

    1

    8

    1

    CHEMISTRY MARKING SCHEME

    SET -56/2

    Compt. July, 2015

  • 2

    9 i)

    ii) Molality (m) is defined as the number of moles of the solute per kilogram (kg) of the

    solvent. Or

    1

    1

    10 Zero order : mol L-1

    s-1

    Second order : L mol-1

    s-1

    1

    1

    11 i) It lowers the melting point of alumina / acts as a solvent. ii)

    Roasting Calcination

    Ore is heated in a regular supply of air Heating in a limited supply or

    absence of air.

    (Or with equation)

    iii) It is a process of separation of different components of a mixture which are differently adsorbed on a suitable adsorbent.

    OR

    1

    1

    1

    11

    (any 6 correct equations)

    6 x

    = 3

    12 Disproportionation : The reaction in which an element undergoes self-oxidation and self-

    reduction simultaneously. For example

    2Cu+ (aq) Cu

    2+ (aq) + Cu(s)

    (Or any other correct equation)

    1

    1

    13 i) Hexaamminecobalt(III) chloride

    ii) Tetrachlorido nickelate(II)

    iii) Potassium hexacyanoferrate(III)

    1

    1

    1

  • 3

    14 i) 2-bromobutane

    ii) 1, 3-dibromobenzene

    iii) 3-choloropropene

    1

    1

    1

    15

    i)

    ii)

    1

    1

    1

    16

    i)

    ii)

    iii)

    1

    1

    1

    17 i) Peptide linkage in proteins, -amino acids are connected to each other by peptide bond or peptide linkage (-CONH- bond).

    ii) Primary structure - each polypeptide in a protein molecule having amino acids which

    are linked with each other in a specific sequence.

    iii) Denaturation - When a protein is subjected to physical change like change in

    temperature or chemical change like change in pH, protein loses its biological activity.

    1

    1

    1

    18 Copolymerisation is a polymerisation reaction in which a mixture of more than one monomeric

    species is allowed to polymerise and form a copolymer.

    1

    1

  • 4

    (or any other correct example)

    1

    19 r =

    r=

    r = 1.44 x cm

    1

    1

    1

    20 cane sugar = X

    Therefore, ccane sugar = cX (where c is molar concentration)

    =

    =

    MX =

    gmol

    -1

    MX = 59.9 or 60 gmol-1

    1

    1

    1

    21 k=

    log

    60 s-1

    =

    log

    t=

    log 10

    t=

    s

    t= 0.0384 s

    1

    1

    1

    22 i) It is a process of removing the dissolved substance from a colloidal solution by means

    of diffusion through a semi - permeable membrane.

    ii) The movement of colloidal particles under an applied electric potential towards

    oppositely charged electrode is called electrophoresis.

    iii) Colloidal particles scatter light in all directions in space. This scattering of light

    illuminates the path of beam in the colloidal dispersion.

    1

    1

    1 23 i) Aspartame, Saccharin (any one)

    ii) No iii) Social concern, empathy, concern, social awareness (any 2 )

    1

    1

    2 24 a) Due to relatively stable half filled p-orbitals of group 15 elements

    b) i) CaF2 + H2SO4 CaSO4 + 2HF

    ii)

    iii)

    OR

    2

    1

    1

    1

  • 5

    24 a) i)

    ii)

    b) i)Due to small size of nitrogen, the lone pair of electron on nitrogen is localized/ easily

    available for donation.

    ii)Because they need only one electron to attain stable/noble gas configuration.

    iii)

    1

    1

    1

    1

    1

    25 a) i)

    ii)

    b) i)Add NaHCO3, benzoic acid will give brisk effervescence of CO2 whereas ethylbenzoate

    will not.

    ii)Add NaOH and I2, acetophonone forms yellow ppt of iodoform on heating whereas

    benzaldehyde will not.

    iii)Add neutral FeCl3, phenol gives violet colouration whereas benzoic acid does not.

    1

    1

    1

    1

  • 6

    (or any other correct test)

    OR 1

    25 a) i)

    ii)

    b) i)

    ii)

    iii)

    1

    1

    1

    1

    1

    26 E0cell = E

    0Sn2+ / Sn - E

    0Zn2+ / Zn

    = - 0.14V (- 0.76V) = 0.62V

    rG0 = -n F E

    0cell

    = - 2 x 96500 C mol-1

    x 0.62 V

    = - 119660 J mol-1

    Ecell = E0

    cell -

    log

    Ecell = 0.62 -

    log

    OR

    1

    1

    1

    1

    1

    26 a) The conductivity of a solution at any given concentration is the conductance of one unit

    volume of solution kept between two platinum electrodes with unit area of cross section

    and at a distance of unit length.

    Molar conductivity of a solution at a given concentration is the conductance of the volume

    V of solution containing one mole of electrolyte kept between two electrodes with area of

    cross section A and distance of unit length.

    Molar conductivity increases with decrease in concentration.

    1

  • 7

    Dr. Sangeeta Bhatia Sh. S.K. Munjal Sh. D.A. Mishra

    Ms. Garima Bhutani

    b)E0cell = E

    0C - E

    0A

    = 0.80V 0.77V = 0.03V

    rG0 = -n F E

    0cell

    = - 1 x 96500 C mol-1

    x 0.03 V

    = - 2895 J mol-1

    Log Kc=

    Log Kc=

    Log Kc= 0.508

    1

  • 56/1/2 1 [P.T.O.

    .

    Roll No.

    ( ) CHEMISTRY (Theory)

    : 3 ] [ : 70 Time allowed : 3 hours ] [ Maximum Marks : 70

    ::::

    (i) (ii) - 1 5 - 1 (iii) - 6 10 - 2 (iv) - 11 22 - 3 (v) - 23 4 (vi) - 24 26 - 5 (vii)

    Series : SSO/1/C 56/1/2

    - 11 - - - - 26 , - 15 - 10.15

    10.15 10.30 - -

    Please check that this question paper contains 11 printed pages. Code number given on the right hand side of the question paper should be written on the

    title page of the answer-book by the candidate. Please check that this question paper contains 26 questions. Please write down the Serial Number of the question before attempting it. 15 minutes time has been allotted to read this question paper. The question paper will be

    distributed at 10.15 a.m. From 10.15 a.m. to 10.30 a.m., the students will read the question paper only and will not write any answer on the answer-book during this period.

    . Code No.

    - - Candidates must write the Code on the title page of the answer-book.

    SET 2

  • 56/1/2 2

    General Instructions : (i) All questions are compulsory. (ii) Q. No. 1 to 5 are very short answer questions and carry 1 mark each. (iii) Q. No. 6 to 10 are short answer questions and carry 2 marks each. (iv) Q. No. 11 to 22 are also short answer questions and carry 3 marks each. (v) Q. No. 23 is a value based question and carry 4 marks. (vi) Q. No. 24 to 26 are long answer questions and carry 5 marks each. (vii) Use log tables if necessary, use of calculator is not allowed.

    1.

    In reference to surface chemistry, define dialysis.

    2. [Ni(NH3)6]Cl2 (IUPAC)

    What is the IUPAC name of the complex [Ni(NH3)6]Cl2 ?

    3.

    3-

    Draw the structure of 3-methylpentanal.

    4. :

    C6H5N2Cl + H3PO2 + H2O - - -

    Complete the following reaction equation :

    C6H5N2Cl + H3PO2 + H2O - - -

    5. : (z) ? What is the no. of atoms per unit cell (z) in a body-centred cubic structure ?

  • 56/1/2 3 [P.T.O.

    6. ?

    :

    (i) (ii) What is meant by disproportionation ? Give an example of a disproportionation

    reaction in aqueous solution.

    OR Suggest reasons for the following features of transition metal chemistry :

    (i) The transition metals and their compounds are usually paramagnetic. (ii) The transition metals exhibit variable oxidation states.

    7. :-

    CH3CH2OH H+

    443 K

    CH2 = CH2 + H2O

    Explain the mechanism of dehydration steps of ethanol :-

    CH3CH2OH H+

    443 K

    CH2 = CH2 + H2O

    8. ?

    Define osmotic pressure of a solution. How is the osmotic pressure related to the

    concentration of a solute in a solution ?

    9. :

    (i) (t)

    (ii) (k) Define the following terms :

    (i) Half-life of a reaction (t)

    (ii) Rate constant (k)

  • 56/1/2 4

    10. :

    (i) H2SO4

    (ii) XeF2

    Draw the structures of the following :

    (i) H2SO4

    (ii) XeF2

    11. :

    (i) [Co(NH3)5(NO2)]2+

    (ii) [Co(en)3]Cl3 (en = )

    (iii) [Pt(NH3)2Cl2]

    Indicate the types of isomerism exhibited by the following complexes :

    (i) [Co(NH3)5(NO2)]2+

    (ii) [Co(en)3]Cl3 (en = ethylene diamine)

    (iii) [Pt(NH3)2Cl2]

    12. (IUPAC) : (i) CH3 CH |

    OH

    CH2 CH3

    (ii)

    (iii) CH3 CH3|

    C | CH3

    CH2 Cl

  • 56/1/2 5 [P.T.O.

    Name the following according to IUPAC system :

    (i) CH3 CH | OH

    CH2 CH3

    (ii)

    (iii) CH3 CH3|

    C | CH3

    CH2 Cl

    13. ?

    (i) -2-

    (ii)

    (iii) p-

    How are the following conversions carried out ?

    (i) Propene to propane-2-ol (ii) Benzyl chloride to Benzyl alcohol (iii) Anisole to p-Bromoanisole

    14. A B

    Br2 KOH C C C6H7N

    A, B C (IUPAC)

    An aromatic compound A on treatment with aqueous ammonia and heating forms compound B which on heating with Br2 and KOH forms a compound C of

    molecular formula C6H7N. Write the structures and IUPAC names of compounds A, B

    and C.

  • 56/1/2 6

    15. ? How are vitamins classified ? Name the vitamin responsible for the coagulation of blood.

    16. :

    (i) -S (ii) (iii) Write the names and structures of the monomers of the following polymers : (i) Buna-S (ii) Neoprene (iii) Teflon

    17. :

    (i) (ii) (iii) F- Define the following : (i) Schottky defect (ii) Frenkel defect (iii) F-centre

    18. (C2H4O2) 45 g 600 g

    (i) (ii) ( : Kf = 1.86 K kg mol1)

    45 g of ethylene glycol (C2H4O2) is mixed with 600 g of water. Calculate (i) the freezing point depression and (ii) the freezing point of the solution (Given : Kf of water = 1.86 K kg mol1)

  • 56/1/2 7 [P.T.O.

    19. 500 K 700 K : 0.02 s1 0.07 s1 , Ea (R = 8.314 J K1 mol1)

    The rate constants of a reaction at 500 K and 700 K are 0.02 s1 and 0.07 s1 respectively. Calculate the value of activation energy, Ea. (R = 8.314 J K1 mol1)

    20. :

    (i) (ii) (iii) - ( ) Define the following terms :

    (i) Electrophoresis (ii) Adsorption (iii) Shape selective catalysis

    21. :

    (i) (ii) (iii)

    (Pig) ? Outline the principles of refining of metals by the following methods :

    (i) Distillation (ii) Zone refining (iii) Electrolysis OR

    Write down the reactions taking place in different zones in the blast furnace during the extraction of iron. How is pig iron different from cast iron ?

  • 56/1/2 8

    22. ? ?

    What is lanthanoid contraction ? What are the consequences of lanthanoid contraction ?

    23. -

    -

    (i)

    (ii) ?

    (iii) ?

    Ramesh went to a departmental store to purchase groceries. On one of shelves he noticed sugar-free tablets. He decided to buy them for his grandfather who was a diabetic. There were three types of sugar-free tablets. Ramesh decided to buy sucrolose which was good for his grandfathers health.

    (i) Name another sugar free tablet which Ramesh did not buy.

    (ii) Was it right to purchase such medicines without doctors prescription ?

    (iii) What quality of Ramesh is reflected above ?

    24. (a) :

    (i) Cu + HNO3()

    (ii) P4 + NaOH+ H2O

    (b) (i) R3P = O R3N = O ? (R = )

    (ii) ?

    (iii) ?

  • 56/1/2 9 [P.T.O.

    (a) : (i) (ii) H2SO4

    (b) , ,

    (a) Complete the following chemical reaction equations : (i) Cu + HNO3(dilute) (ii) P4 + NaOH+ H2O

    (b) (i) Why does R3P = O exist but R3N = O does not ? (R = alkyl group)

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

    (iii) Why are halogens coloured ?

    OR

    (a) Write balanced equations for the following reactions :

    (i) Chlorine reacts with dry slaked lime.

    (ii) Carbon reacts with concentrated H2SO4.

    (b) Describe the contact process for the manufacture of sulphuric acid with special reference to the reaction conditions, catalysts used and the yield in the process.

    25. (a) :

    (i)

    (ii) -

    (b) ?

    (i)

    (ii) m-

    (iii) 3-

  • 56/1/2 10

    (a) : (i) (ii) (b) :

    (i) CH3 C | |O

    CH3 LiAlH4

    ?

    (ii)

    CHO

    HNO3 / H2SO4

    273 283 K ?

    (iii) CH3 COOH PCl5

    ?

    (a) Describe the following giving chemical equations : (i) De-carboxylation reaction (ii) Friedel-Crafts reaction (b) How will you bring about the following conversions ? (i) Benzoic acid to Benzaldehyde (ii) Benzene to m-Nitroacetophenone (iii) Ethanol to 3-Hydroxybutanal OR (a) Describe the following actions : (i) Acetylation (ii) Aldol condensation (b) Write the main product in the following equations :

    (i) CH3 C | |O

    CH3 LiAlH4

    ?

    (ii)

    CHO

    HNO3 / H2SO4

    273 283 K ?

    (iii) CH3 COOH PCl5

    ?

  • 56/1/2 11 [P.T.O.

    26. (a) : (i) (^m) (ii) (iii) (b) : (i) (ii)

    (a) -

    (b) Ni(s) | Ni2+(aq) || Ag+(aq) | Ag(s) 25 C

    ?

    ENi2+/Ni= 0.25 V, EAg+/Ag= 0.80 V.

    (a) Define the following terms : (i) Molar conductivity (^m) (ii) Secondary batteries (iii) Fuel cell (b) State the following laws : (i) Faraday first law of electrolysis (ii) Kohlrauschs law of independent migration of ions

    OR

    (a) Define the term degree of dissociation. Write an expression that relates the molar conductivity of a weak electrolyte to its degree of dissociation.

    (b) For the cell reaction Ni(s) | Ni2+(aq) || Ag+(aq) | Ag(s) Calculate the equilibrium constant at 25 C. How much maximum work would

    be obtained by operation of this cell ?

    ENi2+/Ni= 0.25 V and EAg+/Ag= 0.80 V.

    ___________

  • 56/1/2 12

  • 1

    Qu

    es. Value points Marks

    1 It is a process of removing a dissolved substance from a colloidal solution by means of diffusion

    through a suitable membrane.

    1

    2 Hexaamninenickel (II) chloride 1

    3

    1

    4

    (where Ar is C6H5)

    1

    5 2 1

    6 Disproportionation : The reaction in which an element undergoes self-oxidation and self-

    reduction simultaneously. For example

    2Cu+ (aq) Cu

    2+ (aq) + Cu(s)

    (Or any other correct equation)

    OR

    1

    1

    6 i) Due to presence of unpaired electrons in d-orbitals. ii) Due to incomplete filling of d-orbitals.

    1

    1

    7

    1

    8 The external pressure which is applied on solution side to stop the flow of solvent across the

    semi-permeable membrane.

    The osmotic pressure is directly proportional to concentration of the solution. / = CRT

    1

    1

    CHEMISTRY MARKING SCHEME

    SET -56/1/2

    Compt. July, 2015

  • 2

    9 The half-life of a reaction is the time in which the concentration of a reactant is reduced to one-

    half of its initial concentration.

    Rate constant is the rate of reaction when the concentration of the reactant is unity.

    1

    1

    10

    i) ii)

    1+1

    11 a) Linkage isomerism b) Optical isomerism c) Cis - trans / Geometrical isomerism

    1

    1

    1

    12 a) Butan 2 ol b) 2 bromotoluene c) 2, 2-dimethylchlorpropane

    1

    1

    1

    13 i)

    ii)

    iii)

    1

    1

    1

    14

    A Benzoic acid

    B Benzamide

    C - Aniline

    +

    +

  • 3

    +

    15 Fat soluble vitamin- Vitamin A, D

    Water soluble vitamin-Vitamin B,C

    Vitamin K

    +

    +

    1

    16 i)

    ii)

    iii)

    +

    +

    +

    17 i) The defect in which equal number of cations and anions are missing from the lattice. ii) Due to dislocation of smaller ion from its normal site to an interstitial site. iii) Anionic vacancies are occupied by unpaired electron.

    1

    1

    1

    18 i) Tf = Kf m

    Tf = Kf

    Tf =

    Tf =2.325K or 2.3250

    C

    ii) Tf0- Tf = 2.325

    0 C

    O0C - Tf = 2.325

    0 C

    Tf = - 2.3250

    C or 270.675 K

    1

    1

    19

    1

    1

    1

    20 i) The movement of colloidal particles under an applied electric potential towards oppositely charged electrode is called electrophoresis.

    ii) The accumulation of molecular species at the surface rather than in the bulk of a solid or liquid is termed adsorption.

    iii) The catalytic reaction that depends upon the pore structure of the catalyst and the size of the

    reactant and product molecules is called shape-selective catalysis.

    1

    1

    1

  • 4

    21 i) The impure metal is evaporated to obtain the pure metal as distillate. ii) This method is based on the principle that the impurities are more soluble in the melt than in

    the solid state of the metal.

    iii) The impure metal is made to act as anode. A strip of the same metal in pure form is used as cathode. They are put in a suitable electrolytic bath containing soluble salt of the same metal.

    The more basic metal remains in the solution and the less basic ones go to the anode mud.

    OR

    1

    1

    1

    ( any four correct equations) Cast iron has lower carbon content (about 3%) than pig iron / cast iron is hard & brittle whereas pig iron is soft.

    x 4

    = 2

    1

    22 The steady decrease in atomic radii from La to Lu due to imperfect shielding of 4f orbital. Consequences i) Members of third transition series have almost identical radii as coresponding members

    of second transition series.

    ii) Difficulty in separation.

    1

    1+1

    23 i) Aspartame, Saccharin (any one) ii) No iii) Social concern, empathy, concern, social awareness (any 2 )

    1

    1

    2

    24 a) i)

    ii)

    b) i) Due to absence of d-orbital, nitrogen cannot expand its valency beyond four. ii) Because of p p multiple bonding in dioxygen which is absent in sulphur. iii) Due to excitation of electron by absorption of radiation from visible region.

    OR

    1

    1

    1

    1

    1

    a) i)

    ii)

    b) It is manufactured by Contact Process which involves following steps:

    i) burning of sulphur or sulphide ores in air to generate SO2.

    ii) conversion of SO2 to SO3 by the reaction with oxygen in the presence of a catalyst (V2O5)

    iii) absorption of SO3 in H2SO4 to give Oleum (H2S2O7). The oleum obtained is diluted to give

    sulphuric acid

    Reaction condition pressure of 2 bar and temperature of 720 K Catalyst used is V2O5

    1

    1

    1

    1

    1

  • 5

    Yield 96 98% pure

    25 a) i) Carboxylic acids lose carbon dioxide to form hydrocarbons when their sodium salts are heated with sodalime (NaOH and CaO).

    ii) When the alkyl / acyl group is introduced at ortho and para positions by reaction

    with alkyl halide / acyl halide in the presence of anhydrous aluminium chloride (a Lewis

    acid) as catalyst.

    (Note : Award full marks if correct equation is given )

    b) i)

    ii)

    iii)

    (or any other correct method)

    OR

    1

    1

    1

    1

    1

    25 a) i) When the acyl groups are introduced at ortho and para positions by reaction with acyl halide in the presence of anhydrous aluminium chloride (a Lewis acid) as catalyst.

    ii) Aldehydes and ketones having at least one -hydrogen undergo a reaction in the presence of dilute alkali as catalyst to form -hydroxy aldehydes (aldol) or hydroxy ketones (ketol), respectively.

    1

    1

  • 6

    (Note : Award full marks if correct equation is given )

    b)i)

    ii)

    iii) CH3COCl

    1

    1

    1

    26 a)i)Molar conductivity of a solution at a given concentration is the conductance of the volume V

    of solution containing one mole of electrolyte kept between two electrodes with area of cross

    section A and distance of unit length.

    ii) Secondary battery- can be recharged by passing current through it in opposite direction so that

    it can be used again.

    iii) Galvanic cells that are designed to convert the energy of combustion of fuels like hydrogen,

    methane, methanol, etc. directly into electrical energy are called fuel cells.

    b)i) The amount of chemical reaction which occurs at any electrode during electrolysis by a

    current is proportional to the quantity of electricity passed through the electrolyte (solution or

    melt).

    ii) Limiting molar conductivity of an electrolyte can be represented as the sum of the individual

    contributions of the anion and cation of the electrolyte.

    OR

    1

    1

    1

    1

    1

    26 a) Degree of dissociation is the extent to which electrolyte gets dissociated into its constituent

    ions.

    b) E

    0cell = E

    0Ag+ / Ag - E

    0Ni2+ / Ni

    = 0.80V 0.25V = 0.55V

    1og Kc =

    =

    log Kc = 18.644

    G0 = - nFE0cell = -2x96500 Cmol

    -1 x 0.55V

    = -106,150 Jmol-1

    Max.work =+106150 Jmol-1

    or 106.150k Jmol-1

    1

    1

    1

  • 7

    Dr. Sangeeta Bhatia Sh. S.K. Munjal Sh. D.A. Mishra

    Ms. Garima Bhutani

  • 56/1 1 [P.T.O.

    .

    Roll No.

    ( ) CHEMISTRY (Theory)

    : 3 ] [ : 70 Time allowed : 3 hours ] [ Maximum Marks : 70

    ::::

    (i) (ii) - 1 5 - 1 (iii) - 6 10 - 2 (iv) - 11 22 - 3 (v) - 23 4 (vi) - 24 26 - 5 (vii) ,

    Series : SSO/C 56/1

    - 12 - - - - 26 , - 15 - 10.15

    10.15 10.30 - -

    Please check that this question paper contains 12 printed pages. Code number given on the right hand side of the question paper should be written on the

    title page of the answer-book by the candidate. Please check that this question paper contains 26 questions. Please write down the Serial Number of the question before attempting it. 15 minutes time has been allotted to read this question paper. The question paper will be

    distributed at 10.15 a.m. From 10.15 a.m. to 10.30 a.m., the students will read the question paper only and will not write any answer on the answer-book during this period.

    . Code No.

    - - Candidates must write the Code on the title page of the answer-book.

    SET 1

  • 56/1 2

    General Instructions : (i) All questions are compulsory. (ii) Question number 1 to 5 are very short answer questions and carry 1 mark each. (iii) Question number 6 to 10 are short answer questions and carry 2 marks each. (iv) Question number 11 to 22 are also short answer questions and carry 3 marks each. (v) Question number 23 is a value based question and carry 4 marks. (vi) Question number 24 to 26 are long answer questions and carry 5 marks each. (vii) Use log tables, if necessary. Use of calculators is not allowed.

    1. AgCl ? What type of stoichiometric defect is shown by AgCl ?

    2. ?

    What are emulsions ? Give an example.

    3. ?

    What is meant by chelate effect ?

    4. (IUPAC) :

    CH3 CH2 CHO

    Write the IUPAC name of the following :

    CH3 CH2 CHO

    5. :

    , p- p-

    Arrange the following in increasing order of basic strength :

    Aniline, p-Nitroaniline and p-Toluidine

  • 56/1 3 [P.T.O.

    6. :

    (i) (x)

    (ii) (m)

    Define the following terms :

    (i) Mole fraction (x)

    (ii) Molality of a solution (m)

    7.

    mol L1

    Write units of rate constants for zero order and for the second order reactions if the

    concentration is expressed in mol L1 and time in second.

    8. :

    (i)

    (ii) NF3 NCl3

    Explain the following :

    (i) Nitrogen is much less reactive than phosphorus.

    (ii) NF3 is an exothermic compound but NCl3 is an endothermic compound.

    9.

    ?

    (i) (ii) H2S

  • 56/1 4

    Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with oxalic acid ? Write the ionic equations for the

    reactions.

    OR

    Describe the oxidising action of potassium dichromate and write the ionic equations for its reaction with (i) an iodide (ii) H2S.

    10.

    Write the mechanism of acid dehydration of ethanol to yield ethene.

    11. fcc 4.077 108 cm ,

    (r)

    Silver crystallises in fcc lattice. If edge length of the unit cell is 4.077 108 cm, then

    calculate the radius of silver atom.

    12. - (M.W. 342) 5 ( ) X 0.877% X

    A 5 percent solution (by mass) of cane-sugar (M.W. 342) is isotonic with 0.877% solution of substance X. Find the molecular weight of X.

    13. 60 s1 1/10

    ?

    The rate constant for a first order reaction is 60 s1. How much time will it take to reduce the initial concentration of the reactant to its 1/10th value ?

  • 56/1 5 [P.T.O.

    14. :

    (i)

    (ii)

    (iii)

    Describe the following processes :

    (i) Dialysis

    (ii) Electrophoresis

    (iii) Tyndall effect

    15. :

    (i) ?

    (ii)

    (iii) ?

    Answer the following :

    (i) What is the role of cryolite in the metallurgy of aluminium ?

    (ii) Differentiate between roasting and calcination.

    (iii) What is meant by the term chromatography ?

    OR

    Write the reactions taking place in different zones of the blast furnace to obtain Iron.

    16. ?

    What is meant by disproportionation ? Give one example of disproportionation reaction in aqueous solutions.

  • 56/1 6

    17. IUPAC :

    (i) [Co(NH3)6]Cl3

    (ii) [NiCl4]2

    (iii) K3[Fe(CN)6]

    Write the IUPAC name of the following :

    (i) [Co(NH3)6]Cl3

    (ii) [NiCl4]2

    (iii) K3[Fe(CN)6]

    18. (IUPAC) :

    (i) CH3 CH | Br

    CH2 CH3

    (ii)

    Br

    Br

    (iii) CH2 = CH CH2 Cl

    Give the IUPAC names of the following compounds :

    (i) CH3 CH | Br

    CH2 CH3

    (ii)

    Br

    Br

    (iii) CH2 = CH CH2 Cl

  • 56/1 7 [P.T.O.

    19. ?

    (i) (ii) -1- (iii) -2- How are the following conversions carried out ? (i) Benzyl chloride to Benzyl alcohol (ii) Ethyl magnesium chloride to Propan-1-ol (iii) Propene to Propan-2-ol

    20. :

    (i) CH3 CH2OH PCl5

    ?

    (ii)

    OH

    + CH3 Cl anhyd. AlCl3

    ?

    (iii) CH3 Cl + CH3CH2 ONa ? Write the major product in the following equations :

    (i) CH3 CH2OH PCl5

    ?

    (ii)

    OH

    + CH3 Cl anhyd. AlCl3

    ?

    (iii) CH3 Cl + CH3CH2 ONa ?

    21. :

    (i) (ii) (iii) Define the following as related to proteins : (i) Peptide linkage (ii) Primary structure (iii) Denaturation

  • 56/1 8

    22.

    Explain the term copolymerization and give two examples of copolymerization.

    23.

    ,

    (i)

    (ii) ?

    (iii) ?

    Neeraj went to the departmental store to purchase groceries. On one of the shelves he noticed sugar free tablets. He decided to buy them for his grandfather who was a diabetic. There were three types of sugar free tablets. He decided to buy sucrolose

    which was good for his grandfathers health.

    (i) Name another sugar free tablet which Neeraj did not purchase.

    (ii) Was it right to purchase such medicines without doctors prescription ?

    (iii) What quality of Neeraj is reflected above ?

    24. rG e.m.f.(E) 25 C :

    Zn(s) | Zn2+(aq) || Sn2+(aq) | Sn(s)

    : EZn2+/Zn

    = 0.76 V; ESn2+/Sn

    = 0.14 V

    F = 96500 C mol1

  • 56/1 9 [P.T.O.

    (a) -

    (b) :

    Fe2+(aq) + Ag+(aq) Fe3+(aq) + Ag(s)

    rG

    (EAg+/Ag

    = 0.80 V; EFe3+/Fe2+

    = 0.77 V)

    Calculate rG and e.m.f. (E) that can be obtained from the following cell under the standard conditions at 25 C :

    Zn(s) | Zn2+(aq) || Sn2+(aq) | Sn(s)

    Given : EZn2+/Zn

    = 0.76 V; ESn2+/Sn

    = 0.14 V

    and F = 96500 C mol1.

    OR

    (a) Define conductivity and molar conductivity for the solution of an electrolyte. Discuss their variation with concentration.

    (b) Calculate the standard cell potential of the galvanic cell in which the following reaction takes place :

    Fe2+(aq) + Ag+(aq) Fe3+(aq) + Ag(s)

    Calculate the rG and equilibrium constant of the reaction also.

    (EAg+/Ag

    = 0.80 V; EFe3+/Fe2+

    = 0.77 V)

  • 56/1 10

    25. (a) 16 15 ?

    (b)

    (i) H2SO4 CaF2 ?

    (ii) ?

    (iii) Ca(OH)2 ?

    (a) :

    (i) BrF3

    (ii) XeO3

    (b) :

    (i) PH3 NH3 ?

    (ii) ?

    (iii) XeOF4

    (a) Elements of Gr. 16 generally show lower value of first ionization enthalpy compared to the corresponding periods of Gr. 15. Why ?

    (b) What happens when

    (i) concentrated H2SO4 is added to CaF2 ?

    (ii) sulphur dioxide reacts with chlorine in the presence of charcoal ?

    (iii) ammonium chloride is treated with Ca(OH)2 ?

    OR

  • 56/1 11 [P.T.O.

    (a) Draw the structure of the following :

    (i) BrF3

    (ii) XeO3

    (b) Answer the following :

    (i) Why is NH3 more basic than PH3 ?

    (ii) Why are halogens strong oxidising agents ?

    (iii) Draw the structure of XeOF4.

    26. (a) :

    (i) p-

    (ii) 4--3--2-

    (b) :

    (i)

    (ii)

    (iii)

    (a) :

    (i)

    (ii) CH3CHO

    (b) ?

    (i) CH3 CH3

    (ii) CH3 CH | OH

    CH2 CHO

    (iii) CH3CH2OH

  • 56/1 12

    (a) Draw the structures of the following :

    (i) p-Methylbenzaldehyde

    (ii) 4-Methylpent-3-en-2-one

    (b) Give chemical tests to distinguish between the following pairs of compounds :

    (i) Benzoic acid and Ethyl benzoate.

    (ii) Benzaldehyde and Acetophenone.

    (iii) Phenol and Benzoic acid.

    OR

    (a) Draw the structures of the following derivatives :

    (i) Propanone oxime

    (ii) Semicarbazone of CH3CHO

    (b) How will you convert ethanal into the following compounds ? Give the chemical equations involved.

    (i) CH3 CH3

    (ii) CH3 CH | OH

    CH2 CHO

    (iii) CH3CH2OH _________

  • 1

    Qu

    es. Value points Marks

    1 Frenkel defect 1

    2 Emulsions are liquid liquid colloidal systems. For example milk, cream (or any other one correct example)

    +

    3 Formation of stable complex by polydentate ligand. 1

    4 Propanal 1

    5 p-Nitroaniline < Aniline < p-Toluidine 1

    6 i)

    ii) Molality (m) is defined as the number of moles of the solute per kilogram (kg) of the

    solvent. Or

    1

    1

    7 Zero order : mol L-1

    s-1

    Second order : L mol-1

    s-1

    1

    1

    8 i) Due to high bond dissociation enthalpy of N N ii) Due to low bond dissociation enthalpy of F2 than Cl2 and strong bond formation

    between N and F

    1

    1

    9 Potassium permanganate is prepared by fusion of MnO2 with an alkali metal hydroxide and an

    oxidising agent like KNO3. This produces the dark green K2MnO4 which disproportionates in a

    neutral or acidic solution to give permanganate.

    Oxalate ion or oxalic acid is oxidised at 333 K:

    OR

    1

    1

    9 i)

    ii)

    1

    1

    CHEMISTRY MARKING SCHEME

    SET -56/1

    Compt. July, 2015

  • 2

    10

    1

    11 r =

    r=

    r = 1.44 x cm

    1

    1

    1

    12 cane sugar = X

    Therefore, ccane sugar = cX (where c is molar concentration)

    =

    =

    MX =

    gmol

    -1

    MX = 59.9 or 60 gmol-1

    1

    1

    1

    13 k=

    log

    60 s-1

    =

    log

    t=

    log 10

    t=

    s

    t= 0.0384 s

    1

    1

    1

    14 i) It is a process of removing the dissolved substance from a colloidal solution by means

    of diffusion through a semi - permeable membrane.

    ii) The movement of colloidal particles under an applied electric potential towards

    oppositely charged electrode is called electrophoresis.

    1

    1

  • 3

    iii) Colloidal particles scatter light in all directions in space. This scattering of light

    illuminates the path of beam in the colloidal dispersion.

    1 15 i) It lowers the melting point of alumina / acts as a solvent.

    ii)

    Roasting Calcination

    Ore is heated in a regular supply of air Heating in a limited supply or

    absence of air.

    (Or with equation)

    iii) It is a process of separation of different components of a mixture which are differently adsorbed on a suitable adsorbent.

    OR

    1

    1

    1

    15

    (any 6 correct equations)

    6 x

    = 3

    16

    Disproportionation : The reaction in which an element undergoes self-oxidation and self-

    reduction simultaneously. For example

    2Cu+ (aq) Cu

    2+ (aq) + Cu(s)

    (Or any other correct equation)

    1

    1

    17 i) Hexaamminecobalt(III) chloride

    ii) Tetrachlorido nickelate(II)

    iii) Potassium hexacyanoferrate(III)

    1

    1

    1

    18 i) 2-bromobutane

    ii) 1, 3-dibromobenzene

    iii) 3-choloropropene

    1

    1

    1

    19

    i)

    ii)

    1

    1

  • 4

    1

    20

    i)

    ii)

    iii)

    1

    1

    1

    21 i) Peptide linkage in proteins, -amino acids are connected to each other by peptide bond or peptide linkage (-CONH- bond).

    ii) Primary structure - each polypeptide in a protein molecule having amino acids which

    are linked with each other in a specific sequence.

    iii) Denaturation - When a protein is subjected to physical change like change in

    temperature or chemical change like change in pH, protein loses its biological activity.

    1

    1

    1

    22 Copolymerisation is a polymerisation reaction in which a mixture of more than one monomeric

    species is allowed to polymerise and form a copolymer.

    (or any other correct example)

    1

    1

    1

    23 i) Aspartame, Saccharin (any one) ii) No iii) Social concern, empathy, concern, social awareness (any 2 )

    1

    1

    2

    24 E0cell = E

    0Sn2+ / Sn - E

    0Zn2+ / Zn

    = - 0.14V (- 0.76V) = 0.62V

    rG0 = -n F E

    0cell

    = - 2 x 96500 C mol-1

    x 0.62 V

    = - 119660 J mol-1

    1

    1

    1

    1

  • 5

    Ecell = E0

    cell -

    log

    Ecell = 0.62 -

    log

    OR

    1

    24 a) The conductivity of a solution at any given concentration is the conductance of one unit

    volume of solution kept between two platinum electrodes with unit area of cross section

    and at a distance of unit length.

    Molar conductivity of a solution at a given concentration is the conductance of the volume

    V of solution containing one mole of electrolyte kept between two electrodes with area of

    cross section A and distance of unit length.

    Molar conductivity increases with decrease in concentration.

    b)E0cell = E

    0C - E

    0A

    = 0.80V 0.77V = 0.03V

    rG0 = -n F E

    0cell

    = - 1 x 96500 C mol-1

    x 0.03 V

    = - 2895 J mol-1

    Log Kc=

    Log Kc=

    Log Kc= 0.508

    1

    1

    25 a) Due to relatively stable half filled p-orbitals of group 15 elements

    b) i) CaF2 + H2SO4 CaSO4 + 2HF

    ii)

    iii)

    OR

    2

    1

    1

    1

    25 a) i)

    ii)

    b) i)Due to small size of nitrogen, the lone pair of electron on nitrogen is localized/ easily

    1

    1

    1

  • 6

    available for donation.

    ii)Because they need only one electron to attain stable/noble gas configuration.

    iii)

    1

    1

    26 a) i)

    ii)

    b) i)Add NaHCO3, benzoic acid will give brisk effervescence of CO2 whereas ethylbenzoate

    will not.

    ii)Add NaOH and I2, acetophonone forms yellow ppt of iodoform on heating whereas

    benzaldehyde will not.

    iii)Add neutral FeCl3, phenol gives violet colouration whereas benzoic acid does not. (or any other correct test)

    OR

    1

    1

    1

    1

    1

    26 a) i)

    ii)

    b) i)

    ii)

    1

    1

    1

    1

  • 7

    Dr. Sangeeta Bhatia Sh. S.K. Munjal Sh. D.A. Mishra

    Ms. Garima Bhutani

    iii)

    1

  • 56/1/1 1 [P.T.O.

    .

    Roll No.

    ( ) CHEMISTRY (Theory)

    : 3 ] [ : 70 Time allowed : 3 hours ] [ Maximum Marks : 70

    ::::

    (i) (ii) - 1 5 - 1 (iii) - 6 10 - 2 (iv) - 11 22 - 3 (v) - 23 4 (vi) - 24 26 - 5 (vii)

    Series : SSO/1/C 56/1/1

    - 11 - - - - 26 , - 15 - 10.15

    10.15 10.30 - -

    Please check that this question paper contains 11 printed pages. Code number given on the right hand side of the question paper should be written on the

    title page of the answer-book by the candidate. Please check that this question paper contains 26 questions. Please write down the Serial Number of the question before attempting it. 15 minutes time has been allotted to read this question paper. The question paper will be

    distributed at 10.15 a.m. From 10.15 a.m. to 10.30 a.m., the students will read the question paper only and will not write any answer on the answer-book during this period.

    . Code No.

    - - Candidates must write the Code on the title page of the answ