Chemistry Chemical Bonding NUMS 2023
PMDC Verified Question 37 of 102
The factor which is not affecting bond length is:
A
Presence of multiple bonds
B
Nature of hybridization present
C
Difference in electronegativity between the two bonded atoms
D
Ionization energies of the two bonded atoms
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Propolis Cognitive Error Autopsy

Official Correct Choice:
Option D: Ionization energies of the two bonded atoms
Concept:

Bond length is the internuclear distance between two bonded atoms. It is physically determined by orbital size, bond order, and electrostatic polarity.

Formula:

$$ \text{Bond Length} \propto \text{Radius} + \text{Radius} - \text{Polarity corrections} $$

Solution:

  • Multiple bonds: Increase bond order, pulling atoms closer (decreases length).


  • Hybridization: More s-character (e.g., sp vs sp3) makes orbitals smaller, decreasing bond length.


  • Electronegativity diff: Creates partial charges causing electrostatic attraction, shortening the bond (Schomaker-Stevenson rule).


  • Ionization energy: While related to general atomic properties, it does not directly act as a mechanical factor altering the geometric distance of a formed covalent bond.


Why other options are incorrect:

  • Option A, Option B, Option C: These are the three primary, direct determinants of covalent bond length.

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