Is the molecule in which the intramolecular forces are strongest — Bonding Chemistry Question

STEPS:

1. Define Intramolecular Forces: First, distinguish between *inter*molecular forces (between molecules) and *intra*molecular forces (within a molecule). In this context, intramolecular forces refer to the chemical bonds (covalent bonds) holding the atoms together.
2. Identify the Core Concept: The strength of a covalent bond is primarily determined by its bond order, which is the number of shared electron pairs between two atoms. Generally, triple bonds are stronger than double bonds, which are stronger than single bonds.
3. Analyze the Bond Order for Each Option:
* $N_2$ (C): Nitrogen has 5 valence electrons. To achieve an octet, two nitrogen atoms share three pairs of electrons, forming a triple bond.
* $O_2$ (D): Oxygen has 6 valence electrons and forms a double bond to complete its octet.
* $F_2$ (E): Fluorine has 7 valence electrons and forms a single bond.
* $BeCl_2$ (A): Beryllium forms single bonds with each chlorine atom.
* $SO_2$ (B): As established in the previous question, $SO_2$ is a resonance hybrid where the bonds are intermediate between single and double bonds (a bond order of 1.5).
4. Compare Bond Strengths: Compare the bond types identified. A triple bond requires significantly more energy to break than double, single, or intermediate resonance bonds.
5. Conclusion: Because $N_2$ contains a triple bond, it has the highest bond order and thus the strongest intramolecular forces among the choices provided.

WHY_OTHERS_WRONG:

• $BeCl_2$ (A) and $F_2$ (E): These molecules contain only single bonds, which are the weakest type of covalent bond compared to double or triple bonds.
• $SO_2$ (B): This molecule is a resonance hybrid with a bond order of approximately 1.5; while stronger than a single bond, it is weaker than a triple bond.
• $O_2$ (D): This molecule contains a double bond, which is stronger than a single bond but lacks the three shared electron pairs that make the triple bond in $N_2$ superior in strength.