JEE Main 2021 B.E./B.Tech Question Paper with Answer Key in Odiya (July 27, 2021- Forenoon Session)

JEE Main Questions

• 1.

  Consider the following reaction:

  

  The product \(Y\) formed is:

  • 2-methylhex-3-yne
  • 2-methylhex-2-yne
  • 5-methylhex-2-yne
  • Isopropylbut-1-yne
    
  View Solution

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• 2.

  The oxidation state of chromium in the final product formed in the reaction between KI and acidified $K_2Cr_2O_7$ solution is:

  • +3
  • +6
  • +2
  • +4
  View Solution

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• 3.

  The two projectiles are projected with the same initial velocities at the 15° and 30° with respect to the horizontal. The ratio of their ranges is 1:x. The value of \(x\) is
  

  • \(\sqrt{2}\)
    
  • \(\sqrt{3}\)
    
  • \(2\sqrt{5}\)
    
  • \(\frac{1}{\sqrt{2}}\)
  View Solution

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• 4.

  Find out the statements which are not true.
  A. Resonating structures with more covalent bonds and less charge separation are more stable.
  B. In electromeric effect, an unsaturated system shows +E effect with nucleophile and –E effect with electrophile.
  C. Inductive effect is responsible for high melting point, boiling point and dipole moment of polar compounds.
  D. The greater the number of alkyl groups attached to the doubly bonded carbon atoms, higher is the heat of hydrogenation.
  E. Stability of carbanion increases with increase in s-character of the carbon carrying negative charge.
  

  • B, D & E only
    
  • A, D & E only
    
  • B & D only
    
  • A, C & D only
    
  View Solution

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• 5.

  The correct order of the rate of the reaction for the following reaction with respect to nucleophiles is :
  \( CH_3Br + Nu^\ominus \rightarrow CH_3Nu + Br^\ominus \)

  • \( CH_3COO^\ominus>PhO^\ominus>^\ominus OH>ClO_4^\ominus \)
  • \( ClO_4^\ominus>CH_3COO^\ominus>^\ominus OH>PhO^\ominus \)
  • \( ^\ominus OH>PhO^\ominus>CH_3COO^\ominus>ClO_4^\ominus \)
  • \( PhO^\ominus>^\ominus OH>CH_3COO^\ominus>ClO_4^\ominus \)
  View Solution

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• 6.

  Given below are some of the statements about Mn and \( Mn_2O_7 \). Identify the correct statements.
  A. Mn forms the oxide \( Mn_2O_7 \), in which Mn is in its highest oxidation state.
  B. Oxygen stabilizes the Mn in higher oxidation states by forming multiple bonds with Mn.
  C. \( Mn_2O_7 \) is an ionic oxide.
  D. The structure of \( Mn_2O_7 \) consists of one bridged oxygen.
  Choose the correct answer from the options given below :

  • A, B and D Only
  • A, C and D Only
  • A, B and C Only
  • A, B, C and D
  View Solution