JEE Main · 2023 · Shift-ImediumBOND-064

Consider the following statements: (A) NF3 molecule has a trigonal planar structure. (B) Bond length of N2 is shorter…

Chemical Bonding · Class 11 · JEE Main Previous Year Question

Question

Consider the following statements:

(A) NF3\mathrm{NF_3} molecule has a trigonal planar structure. (B) Bond length of N2\mathrm{N_2} is shorter than O2\mathrm{O_2}. (C) Isoelectronic molecules or ions have identical bond order. (D) Dipole moment of H2S\mathrm{H_2S} is higher than that of water molecule.

Choose the correct answer:

Options
  1. a

    (A) and (B) are correct

  2. b

    (A) and (D) are correct

  3. c

    (C) and (D) are correct

  4. d

    (B) and (C) are correct

Correct Answerd

(B) and (C) are correct

Detailed Solution

🧠 Evaluate each statement against known molecular properties.

(A) "\ceNF3\ce{NF3} is trigonal planar"Incorrect. N in \ceNF3\ce{NF3} has 3 bonds + 1 lone pair = 4 electron groups → sp³ hybridised → trigonal pyramidal, not planar. Lone pairs on N make it pyramidal.

(B) "Bond length of \ceN2\ce{N2} is shorter than \ceO2\ce{O2}"Correct. \ceN2\ce{N2} has a triple bond (BO = 3, length ≈ 110 pm); \ceO2\ce{O2} has a double bond (BO = 2, length ≈ 121 pm). Triple bonds are shorter than double bonds. ✓

(C) "Isoelectronic molecules have identical bond order"Correct. Isoelectronic species have the same number of electrons and therefore identical MO filling, giving identical bond orders. (e.g. \ceN2\ce{N2}, CO, \ceNO+\ce{NO+} are all isoelectronic with BO = 3.) ✓

(D) Relates to dipole moment — this statement contains an error (e.g. \ceNF3\ce{NF3} dipole > \ceNH3\ce{NH3} dipole is incorrect since in \ceNF3\ce{NF3}, the N–F bond dipoles oppose the lone-pair moment, reducing the net dipole).

Answer: (d) B and C are correct\boxed{\text{Answer: (d) B and C are correct}}

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Consider the following statements: (A) NF3 molecule has a trigonal planar structure. (B) Bond… (JEE Main 2023) | Canvas Classes