Nitrogen gas is an extremely stable molecule because its structure contains which of the following?
A.
Resonance bonds
B.
Ionic bonds
C.
Triple covalent bonds
D.
Hydrogen bonds
The Correct answer and Explanation is:
The correct answer is C. Triple covalent bonds.
Nitrogen gas (N₂) is a diatomic molecule consisting of two nitrogen atoms. The stability of this molecule is largely attributed to the nature of the chemical bonds between the nitrogen atoms. In N₂, each nitrogen atom shares three pairs of electrons with the other, forming a triple covalent bond. This type of bonding is crucial to understanding why nitrogen gas is so stable.
Triple Covalent Bonds
A triple covalent bond involves three pairs of shared electrons between two atoms. In the case of nitrogen gas, the bond can be represented as:
N≡NN \equiv NN≡N
Each nitrogen atom has five valence electrons. By sharing three pairs of electrons, each nitrogen atom achieves a stable octet, which is a complete outer shell of electrons. This configuration is energetically favorable and contributes significantly to the molecule’s stability.
Characteristics of the Triple Bond
- Strength: Triple covalent bonds are among the strongest types of covalent bonds. The bond dissociation energy of a triple bond is considerably higher than that of a single or double bond. For N₂, this high bond dissociation energy makes it difficult to break the bond, contributing to the gas’s stability.
- Bond Length: Triple bonds are shorter than double or single bonds because the increased number of shared electron pairs pulls the bonded atoms closer together. This shorter bond length also contributes to the overall stability of the molecule.
- Inertness: The stability of the N₂ molecule results in its inert nature under normal conditions. Nitrogen gas does not readily react with other substances because breaking the strong triple bond requires a significant amount of energy.
Comparison with Other Bonds
- Resonance Bonds (Option A): Resonance involves the delocalization of electrons within a molecule, but this concept does not directly apply to the diatomic N₂ molecule.
- Ionic Bonds (Option B): Ionic bonds involve the transfer of electrons from one atom to another, resulting in charged ions. N₂ does not involve ion formation but rather covalent bonding.
- Hydrogen Bonds (Option D): Hydrogen bonds are a type of weak intermolecular force between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom. These are not relevant to the bonding in N₂.
In summary, the triple covalent bonds in nitrogen gas are responsible for its exceptional stability and inertness. The strong, short bond between the two nitrogen atoms makes the N₂ molecule particularly stable and resistant to chemical reactions under standard conditions.