write the lewis structure for NF3 and PF5 on the basis of hybrid orbitals
explain the fact that NF3, PF3, and PF5 are stable molecules but NF5 does not exist
The correct answer and explanation is:
Lewis Structures of NF₃ and PF₅ Based on Hybrid Orbitals
- NF₃ (Nitrogen trifluoride)
- Central Atom: Nitrogen (N)
- Valence Electrons: N (5), F (7 × 3) = 26 electrons
- Hybridization: sp³
- Structure: Trigonal pyramidal
- Lone Pair on N: 1
- PF₅ (Phosphorus pentafluoride)
- Central Atom: Phosphorus (P)
- Valence Electrons: P (5), F (7 × 5) = 40 electrons
- Hybridization: sp³d
- Structure: Trigonal bipyramidal
- Lone Pairs on P: 0
Why NF₅ Does Not Exist?
- Electron Configuration & Hybridization:
- Nitrogen (N) belongs to Period 2 and has no available d-orbitals to expand its octet.
- Phosphorus (P) is in Period 3 and can use empty 3d orbitals to accommodate five fluorine atoms.
- Bonding & Steric Effects:
- NF₃ is stable due to the availability of sp³ hybridization.
- NF₅ would require sp³d hybridization, but nitrogen lacks accessible d orbitals.
- The absence of d orbitals in nitrogen prevents it from forming more than four bonds.
- Phosphorus Stability in PF₅:
- Phosphorus, being a third-period element, can expand its octet.
- PF₅ forms a stable trigonal bipyramidal structure using sp³d hybridization.
- Electronegativity & Bond Strength:
- Strong lone-pair repulsion and high electronegativity of fluorine make NF₅ formation unfavorable.
- Phosphorus has a larger atomic size, reducing repulsion in PF₅.
Thus, NF₅ does not exist, whereas NF₃, PF₃, and PF₅ are stable due to differences in hybridization and available orbitals.
Now, I’ll generate the Lewis structure image for NF₃ and PF₅.
I have generated the Lewis structure diagram for NF₃ and PF₅. Let me know if you need any modifications or further explanations!