Question

BF₃ is planar and electron-deficient compound. Hybridization and the number of electrons around the central atom, respectively are

• A. sp² and 8
• B. sp³ and 4
• C. sp³ and 6
• D. sp² and 6

Answer 1

The Correct Option is D

Boron trifluoride (BF₃) is a compound that is both planar and electron-deficient. Understanding its hybridization and the number of electrons around the central atom involves analyzing its electronic structure and bonding.

1. Structure of BF₃:
   • The central atom in BF₃ is Boron (B), which has the atomic number 5, and its electronic configuration is 1s² 2s² 2p¹.
   • Boron typically forms three covalent bonds in BF₃, each with a fluorine atom.
2. Hybridization of Boron:
   • To form three equivalent bonds with the three fluorine atoms, Boron undergoes hybridization.
   • In BF₃, Boron utilizes sp² hybridization. It mixes one s orbital and two p orbitals to form three sp² hybrid orbitals.
   • These sp² hybrid orbitals lie in the same plane and are oriented at 120° angles, resulting in a trigonal planar shape.
3. Electron Count Around Boron:
   • Boron forms three sigma bonds (one with each fluorine atom), using three of its valence electrons.
   • As each bond shares one electron from Boron and one from Fluorine, Boron effectively has 3 electrons of its own and 3 shared electrons in total.
   • Therefore, Boron has a total of 6 electrons in its valence shell in BF₃.
   • BF₃ is electron-deficient because Boron has fewer than 8 electrons in its valence shell, which would be required to satisfy the octet rule.
4. Conclusion:
   • The hybridization of BF₃ is sp², and the number of electrons around the central atom (Boron) is 6.

Thus, the correct option is sp² and 6.