Solved papers for JEE Main & Advanced JEE Main Paper (Held On 26 May 2012)

done JEE Main Paper (Held On 26 May 2012) Total Questions - 30

• question_answer1) The following sets of quantum numbers represent four electrons in an atom.   JEE Main Online Paper (Held On 26-May-2012)  

  (i) \[n=4,l=1\]

  (ii) \[n=4,l=0\]

  (iii)\[n=3,l=2\]

  (iv) \[n=3,l=1\]

  The sequence representing increasing order of energy, is
  A)
  (iii)<(i)<(iv)<(ii)                
  done clear
  B)
  (iv)<(ii)<(iii)<(i)
  done clear
  C)
  (i)<(iii)<(ii)<(iv)                
  done clear
  D)
  (ii)<(iv)<(i)<(iii)
  done clear
  View Answer play_arrow

• question_answer2) 'The substance used as froth stabilisers in forth-floatation process is .   JEE Main Online Paper (Held On 26-May-2012)     
  A)
  Potassium ethyl xanthate
  done clear
  B)
                         Aniline
  done clear
  C)
                         Sodium cyanide
  done clear
  D)
                         Copper sulphate
  done clear
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• question_answer3) The activation energy for a reaction which doubles the rate when the temperature is raised from 298 K to 308 K is.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  \[52.2\,kJ\,mo{{l}^{-1}}\]                            
  done clear
  B)
                         \[39.2\,kJ\,mo{{l}^{-1}}\]
  done clear
  C)
                         \[52.9\,kJ\,mo{{l}^{-1}}\]                            
  done clear
  D)
                         \[29.5\,kJ\,mo{{l}^{-1}}\]
  done clear
  View Answer play_arrow

• question_answer4) Tollen's reagent and Fehling solutions are used to distinguish between.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
   acids and alcohols
  done clear
  B)
                         alkanes and alcohols
  done clear
  C)
                         ketones and aldehydes
  done clear
  D)
                         n-alkaens and branched alkanes
  done clear
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• question_answer5) In the following compounds : the order of basicity is as follows.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  \[IV>III>II>I\]   
  done clear
  B)
                         \[III>I>II>IV\]
  done clear
  C)
                         \[II>III>I>IV\]   
  done clear
  D)
                         \[I>III>II>IV\]
  done clear
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• question_answer6) Maleic acid and fumaric acids are.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  Chain isomers  
  done clear
  B)
                         Functional isomers
  done clear
  C)
                         Tautomers
  done clear
  D)
                         Geometrical isomers
  done clear
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• question_answer7) Which of the following compounds are anti-aromatic .   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  (I) and (V)            
  done clear
  B)
  (II) and (V)
  done clear
  C)
  (I) and (IV)         
  done clear
  D)
  (III) and (VI)
  done clear
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• question_answer8) The freezing point of a 1.00 m aqueous solution of HF is found to be \[-1.91\text{ }{}^\circ C\]. The freezing point constant of water, K. is 1.86 K  kg \[\text{mo}{{\text{l}}^{-1}}\] The percentage dissociation of HF at this concentration is.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  30%                       
  done clear
  B)
  10%
  done clear
  C)
  5.2%                                     
  done clear
  D)
  2.7%
  done clear
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• question_answer9) Which of the following presents the correct order of second ionization enthalpies of C, N, O and F?   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  \[F>O>N>C\]    
  done clear
  B)
                         \[O>N>F>C\]
  done clear
  C)
                         \[C>N>O>F\]    
  done clear
  D)
                         \[O>F>N>C\]
  done clear
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• question_answer10) A transition metal M forms a volatile chloride which has a vapour density of 94.8. If it contains74.75% of chlorine the formula of the metal chloride will be .   JEE Main Online Paper (Held On 26-May-2012)     
  A)
  \[MC{{l}_{3}}\]                 
  done clear
  B)
  \[MC{{l}_{2}}\]
  done clear
  C)
  \[MC{{l}_{4}}\]                 
  done clear
  D)
  \[MC{{l}_{5}}\]
  done clear
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• question_answer11) Among the following species which two have trigonal bipyramidal shape?   JEE Main Online Paper (Held On 26-May-2012)    

  (I) \[N{{I}_{3}}\]

  (II) \[I_{3}^{-}\]

  (III) \[SO_{3}^{2-}\]

  (IV) \[NO_{3}^{-}\]

  A)
  l and III
  done clear
  B)
  IIl and IV
  done clear
  C)
  l and IV                                
  done clear
  D)
  II and III
  done clear
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• question_answer12) Consider the following sequence of reactions \[C{{H}_{3}}CH=C{{H}_{2}}\xrightarrow[700K]{C{{l}_{2}}}A\xrightarrow[420K,12atm]{N{{a}_{2}}C{{O}_{3}}}\]\[B\xrightarrow[(ii)NaOH]{(i)HOCl}C\] Compound 'C' is.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  \[\underset{\begin{align}   & | \\  & CHOH \\  & | \\  & C{{H}_{2}}OH \\ \end{align}}{\mathop{C{{H}_{2}}OH}}\,\]            
  done clear
  B)
  \[C{{H}_{3}}\underset{\begin{smallmatrix}  | \\  OH \end{smallmatrix}}{\mathop{CH}}\,COONa\]
  done clear
  C)
  \[HOC{{H}_{2}}-CH=C{{H}_{2}}\]
  done clear
  D)
  \[C{{H}_{3}}\underset{\begin{smallmatrix}  | \\  OH \end{smallmatrix}}{\mathop{CH}}\,COCl\]
  done clear
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• question_answer13) Fire extinguishers contain \[{{H}_{2}}S{{O}_{4}}\] and which one of the following?   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  \[NaHC{{O}_{3}}\]and\[N{{a}_{2}}C{{O}_{3}}\]
  done clear
  B)
                         \[N{{a}_{2}}C{{O}_{3}}\]
  done clear
  C)
                         \[NaHC{{O}_{3}}\]
  done clear
  D)
                         \[CaC{{O}_{3}}\]
  done clear
  View Answer play_arrow

• question_answer14) Which one of the following depletes ozone layer?   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  CO                                         
  done clear
  B)
                         NO and freons
  done clear
  C)
                         \[S{{O}_{2}}\]                   
  done clear
  D)
                         \[C{{O}_{2}}\]
  done clear
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• question_answer15) Dipole moment is shown by.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  1,2-dichlorobenzene
  done clear
  B)
                         trans 2,3-dichloro-2-butene
  done clear
  C)
                         1,4-chlorobenzene
  done clear
  D)
                          trans-1,2-dinitroethene
  done clear
  View Answer play_arrow

• question_answer16) Which of the following statements is correct?   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  RNA controls the synthesis of proteins.
  done clear
  B)
                         The sugar present in DNA is D-(-)-ribose.                
  done clear
  C)
                         RNA has double stranded a-helix structure.
  done clear
  D)
                          DNA mainly occurs in the cytoplasm of the cell.
  done clear
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• question_answer17) The solubility of\[PB{{I}_{2}}\]at 25°C is \[0.7g\,{{L}^{-1}}.\] The solubility product of\[Pb{{I}_{2}}\] at this temperature is(molar mass of\[Pb{{I}_{2}}=461.2\,g\,\text{mo}{{\text{l}}^{-1}}\]).   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  \[1.40\times {{10}^{-9}}\]                            
  done clear
  B)
                         \[0.14\times {{10}^{-9}}\]
  done clear
  C)
                         \[140\times {{10}^{-9}}\]                             
  done clear
  D)
                         \[14.0\times {{10}^{-9}}\]
  done clear
  View Answer play_arrow

• question_answer18) Bakelite is obtained from phenol by reacting it with.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  Acetaldehyde  
  done clear
  B)
                         Chlorobenzene
  done clear
  C)
                          Formaldehyde  
  done clear
  D)
                         Acetamide
  done clear
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• question_answer19) Among the following the incorrect statement is.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  Density of crystals remains unaffected due to Frenkel defect.
  done clear
  B)
                         In BCC unit cell the void space is 32%.
  done clear
  C)
                         Density of crystals decreases due to Schottky defect.
  done clear
  D)
                         Electrical conductivity of semiconductors and metals increases with increase in temperature.
  done clear
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• question_answer20) Which of the following forms stable + 4 oxidationstate?   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  La(Z=57)                              
  done clear
  B)
                         Eu(Z=63)
  done clear
  C)
                         Ce(Z=58)                             
  done clear
  D)
                          Gd(Z=64)
  done clear
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• question_answer21) Colloidal solutions can be purified by.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  emulsification   
  done clear
  B)
                         electrodialysis
  done clear
  C)
                         peptization        
  done clear
  D)
                         using Tyndall effect
  done clear
  View Answer play_arrow

• question_answer22) Given\[E_{C{{u}^{2+}}/Cu}^{o}=0.34V,E_{C{{u}^{2+}}/Cu}^{o}=0.15V\] Standard electrode potential for the half cell \[C{{u}^{+}}/Cu\]is.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  0.38V                                    
  done clear
  B)
                         0.53V
  done clear
  C)
                         0.19V                                    
  done clear
  D)
                         0.49V
  done clear
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• question_answer23) The complex ion \[{{[Pt(N{{O}_{2}})(Py)(N{{H}_{3}})(N{{H}_{2}}OH)]}^{+}}\]will give.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  2 isomers (Geometrical)
  done clear
  B)
                         3 isomers (Geometrical)
  done clear
  C)
                         6 isomers (Geometrical)
  done clear
  D)
                         4 isomers (Geometrical)
  done clear
  View Answer play_arrow

• question_answer24) The hydration of propyne results in formation of.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
   Acetone                             
  done clear
  B)
                         Propanol-1
  done clear
  C)
                         Propene                             
  done clear
  D)
                         Propanal
  done clear
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• question_answer25) One mole of an ideal gas is expanded isothermally and reversibly to half of its initial pressure. \[\Delta S\]for the process in \[J\,{{K}^{-1}}\,mo{{l}^{-1}}\] is [\[\ell n2=0.693\]and\[R=8.314J/(mol\,K)\]].   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  6.76       
  done clear
  B)
                                         5.76
  done clear
  C)
                         10.76                                    
  done clear
  D)
                         8.03
  done clear
  View Answer play_arrow

• question_answer26) The number of S-S bonds in\[S{{O}_{3}},{{S}_{2}}O_{3}^{2-}{{S}_{2}}O_{6}^{2-}\]and\[{{S}_{2}}O_{8}^{2-}\]respectively are.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  1,0,0,1                                  
  done clear
  B)
  1,0,1,0
  done clear
  C)
  0,1,1,0                                  
  done clear
  D)
  0,1,0,1
  done clear
  View Answer play_arrow

• question_answer27) Sulphonamides act as.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  Antiseptic           
  done clear
  B)
                         Analgesic
  done clear
  C)
                         Antimicrobials  
  done clear
  D)
                         Antipyretic
  done clear
  View Answer play_arrow

• question_answer28) The relationship among most probable velocity, average velocity and root mean square velocity is respectively.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  \[\sqrt{2}:\sqrt{3}:\sqrt{8/\pi }\]             
  done clear
  B)
                         \[\sqrt{2}:\sqrt{8/\pi }:\sqrt{3}\]
  done clear
  C)
                         \[\sqrt{8/\pi }:\sqrt{3}:\sqrt{2}\]             
  done clear
  D)
                         \[\sqrt{3}:\sqrt{8/\pi }:\sqrt{2}\]
  done clear
  View Answer play_arrow

• question_answer29) The number of unpaired electrons in Gadolinium\[[Z=64]\]is.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
   3                                            
  done clear
  B)
                         8
  done clear
  C)
                          6                                            
  done clear
  D)
                         2
  done clear
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• question_answer30) One mole of\[{{O}_{2(g)}}\]and two moles of\[S{{O}_{2(g)}}\] were heated in a closed vessel of one-litre capacity at1098 K. At equilibrium 1.6 moles of\[S{{O}_{3(g)}}\] were found. The equilibrium constant \[{{K}_{c}}\] of the reaction would be.   JEE Main Online Paper (Held On 26-May-2012)  
  A)
  30                                          
  done clear
  B)
                         40
  done clear
  C)
                         80    
  done clear
  D)
                         60
  done clear
  View Answer play_arrow