Docstoc

iit jee 2005 chemistry sol _screening_

Document Sample
iit jee 2005 chemistry sol _screening_ Powered By Docstoc
					                           IIT - JEE 2005 Chemistry Solution (Screening)

1 Sol:   Ans. B
         D - glucopyranose is cyclic form of glucose. Around C - 1 (Newly formed chiral centre, due to cycle formation)
         two isomers are observed. They are called as α and β - anomers.
2 Sol:   Ans. A

                   OH
                            H 3P O   4




                                           n
         H 3 P O 4 a cts a s d e h yd ra ti g a g e n t

3 Sol:   Ans. B

                                               1
         PbO 2 + 2HNO 3 → Pb( NO 3 )3 + H 2 O + O 2
                                               2
4 Sol:   Ans. C

                         CH3
                                     N a O H , I2
         H 3C                                       H 3C   COOH
                                         H+
                    O

         Iodoform test.
5 Sol:   Ans. B
         PhMgBr + Me3COH → Ph - H + Me3COMgBr
6 Sol:   Ans. B
         V4+ and Cu2+ both have one unpaired electron available.
7 Sol:   Ans. C
         Work done against constant external pressure = Pext (V2 - V1)
         In adiabatic condition ∆q = 0 therefore w = ∆u

         ∴ − Pext (V2 − V1 ) = R (T2 − T1 ) [Expansion work is negative]
                              3
                              2

                                                2
         On solving, T2 = T1 −                        .
                                           3 × 0.0821
8 Sol:   Ans. B

         Bi +3 + KI → BiI3 ↓
                             Black

         BiI3 + KI →            K[BiI 4 ]
                            Orange solution

9 Sol:   Ans. C
         Chalocopyrite (CuFeS2)


Tvm Branch: T.C.No: 5/1703/30, Golf Links Road, H.B. Clony, Kowdiar Gardens, Trivandrum, (: 0471-2438271    1
Kochi Branch: Bldg.No.41/352, Mulloth Ambady Lane, Chittoor Road, Kochi - 011, (: 0484 - 2370094,9388465944
Note: Based on the memory
10 Sol: Ans. D
        It is an intramolecular Wurtz reaction.

                         Br




        Cl


11 Sol: Ans. A
        SN1 and SN2, both reactions are possible due to aqueous acetone solution.


12. Sol: Ans. B

                  1
        2H+ +       O + 2e-       → H2O; E0 = +1.23 V
                  2 2
        Fe+2 + 2e-                → Fe(s) ; E0 = -0.44 V
                         1
        Fe(s) + 2H+ +      O → Fe+2 + H2O; E 0 = 1.67 V
                                             cell
                         2 2

        ∆G 0 = − n F E 0 = − 2 × 96.500 × 1.67 = − 322 kJ
                       cell

13. Sol: Ans. B
                                                 ⊕
                  CH3NH2 + HCl → CH 3 N H 3 + Cl −
        Initially 0.1            0.08-
        In solution          0.02          - 0.08

                                  [CH 3 NH 2 ]
                  [OH − ] = K b            +
                                  [CH 3 NH 3 ]

                              5 × 10 −4 × 0.02 5
                  [OH − ] =                   = × 10 − 4
                                   0.08        4

                              K W 10−14 × 4
                  [H + ] =       −
                                   =      −4
                                             = 8 ×10−11
                             [OH ] 5 × 10
14 Sol: Ans. A
        Number of radial nodes = n - l - 1,           so, for 3s: 3 - 0 - 1 = 2
        For 2p: 2 - 1 - 1 = 0
15 Sol: Ans. C
                                                                          Ph
                                       COONa
                                            
        p - MeO - Ph - CHO + (AcO)2O CH 3  → p - M e O                         COOH

16 Sol: Ans. D
        Order of reaction is determined experimentally. It may be fractional.
17 Sol: Ans. C
                                        13.44 1000 
        ∆Tb = i × K b × m = 3 × 0.52 ×       ×      = 0.16
                                        134.4 1000 
Tvm Branch: T.C.No: 5/1703/30, Golf Links Road, H.B. Clony, Kowdiar Gardens, Trivandrum, (: 0471-2438271    2
Kochi Branch: Bldg.No.41/352, Mulloth Ambady Lane, Chittoor Road, Kochi - 011, (: 0484 - 2370094,9388465944
Note: Based on the memory
18 Sol: Ans. C

         CH3                            S O 3H + C H 3C O O N a       CH3                         S O 3N a + C H 3C O O H
                                                                                                                          d
                                                                                                             (W e a k a ci )
                               d
                (S tro n g a ci )

        Above reaction is acid base reaction.
19 Sol: Ans. A


                       O
                                          (S h e e t stru ctu re )
                   O
            O              O


20 Sol. Ans. B
                                    0
                   C
        NO + NO 2 30→ N 2 O 3
                                             Pale blue colour

21 Sol: Ans. A

         rHe    16
              =    = 2 :1
        rCH 4    4

22 Sol: Ans. A
        [Co(NH3)4(Br)2]Cl can show both Geometrical and Ionisation isomerism.
23 Sol: Ans. D

                   O
                                                              Fe            Fe
        O          C l- O            o
                               (N o l n e p a ir)                    Xe                   o
                                                                                  (T w o l n e p a ir)
                                                              Fe            Fe

                   O


               F
        F
               S                     o
                             (O n e l n e pa ir)                                        o
                                                                             (T h re e l n e p a ir)
        F

               F

24 Sol: Ans. D
        Lyophilic solutions are solvent loving in nature. Due to this property, such kind of solutions are self stabilised.
25 Sol: Ans. C
        Point of difference is nature of carbanion 20 carbanions are less stable than 10 carbanions generally.
26 Sol: Ans. C
        Due to layered structure in Black Phosphorous, it is most stable.
27 Sol: Ans. B
        In ZnS, Anions (S-2) are placed in fcc manner and cations (Zn+2) are placed in alternate tetrahedral voids.
28 Sol: Ans. C
        KMnO4 can’t be oxidised by any oxidising agents. Mn is in maximum possible oxidation state of VI.

Tvm Branch: T.C.No: 5/1703/30, Golf Links Road, H.B. Clony, Kowdiar Gardens, Trivandrum, (: 0471-2438271    3
Kochi Branch: Bldg.No.41/352, Mulloth Ambady Lane, Chittoor Road, Kochi - 011, (: 0484 - 2370094,9388465944
Note: Based on the memory

				
DOCUMENT INFO
Shared By:
Stats:
views:3
posted:9/14/2012
language:
pages:3
Description: PREVIOUS YEAR PAPERS CBSE BOARD EXAM AIEEE BITSAT ISAT VITEEE IIT-JEE STUDY MATERIAL PHYSICS CLASS XI XII SAMPLE PAPERS KEY SOLUTIONS ANSWERS QUESTIONS