Question

Consider the following statements:
(A) NF3 molecule has a trigonal planar structure. 
(B) Bond length of N2 is shorter than O2. 
(C) Isoelectronic molecules or ions have identical bond order. 
(D) Dipole moment of H2S is higher than that of water molecule. 
Choose the correct answer from the option below

• (A) and (D) are correct
• (B) and (C) are correct
• (A) and (B) are correct
• (C) and (D) are correct

Hint:

Isoelectronic species have the same number of electrons and bond orders

Answer 1

The Correct Option is B

Let's analyze each statement one by one to determine which are correct:

1. Statement A: NF₃ molecule has a trigonal planar structure.
   NF₃ (Nitrogen Trifluoride) actually has a trigonal pyramidal structure due to the presence of a lone pair on the nitrogen atom, which causes a deviation from the ideal trigonal planar configuration. Therefore, this statement is incorrect.
2. Statement B: Bond length of N₂ is shorter than O₂.
   The bond length of N₂ is indeed shorter than that of O₂ because N₂ has a triple bond, while O₂ has a double bond. A triple bond is stronger and shorter than a double bond, making this statement correct.
3. Statement C: Isoelectronic molecules or ions have identical bond order.
   Isoelectronic species are those having the same number of electrons. Isoelectronic molecules or ions typically have the same bond order. For example, N₂ and CO both have a bond order of 3. Therefore, this statement is correct.
4. Statement D: Dipole moment of H₂S is higher than that of water molecule.
   Water (H₂O) has a dipole moment because of its bent shape and strong electronegativity of oxygen. H₂S also has a bent shape but sulfur is less electronegative than oxygen, leading to a smaller dipole moment. Therefore, this statement is incorrect.

Based on the analysis, statements (B) and (C) are correct.