MCQ Detailed View

Beryllium chloride (BeCl₂) is a linear molecule in which beryllium is bonded to two chlorine atoms. To form equivalent bonds, the central atom undergoes hybridization, combining its atomic orbitals to produce hybrid orbitals suitable for bonding.

Beryllium has the electronic configuration 1s² 2s². In BeCl₂, the 2s orbital and one 2p orbital mix to form two sp hybrid orbitals, which are oriented linearly at 180°. This explains the linear geometry of the molecule. The remaining 2p orbital on beryllium remains unhybridized.

The sp hybridization is different from sp² hybridization, which forms three hybrid orbitals in a trigonal planar arrangement, or sp³ hybridization, which forms four hybrid orbitals in a tetrahedral geometry. The option dsp² is used for central atoms in coordination complexes with square planar geometry, which does not apply to BeCl₂.

Understanding hybrid orbitals helps explain bond angles, molecular geometry, and bonding properties. In BeCl₂, the sp hybrid orbitals result in a linear arrangement, making the molecule nonpolar despite polar Be–Cl bonds. Hybridization theory also helps predict the reactivity, bond lengths, and physical properties of molecules.

BeCl₂ is a classic example in physical chemistry for introducing students to linear molecules and the concept of sp hybridization. Recognizing that BeCl₂ uses sp hybrid orbitals is essential for understanding molecular shape, bond formation, and chemical behavior in simple molecules.