Draw the Lewis structure for BrCl 4 -. The molecular geometry (molecular shape) and the hybridization of the central atom
- Square Planar, sp3d2
- Octahedral, sp3d2
- Trigonal bipyramidal, sp3d
- Tetrahedral, sp3
The correct answer and explanation is:
Correct Answer:
1. Square Planar, sp³d²
Explanation:
To determine the Lewis structure, molecular geometry, and hybridization of BrCl₄⁻, let’s proceed step by step:
1. Lewis Structure:
- Central Atom: Bromine (Br) is the central atom because it is less electronegative than chlorine.
- Valence Electrons: Bromine has 7 valence electrons, and each of the four chlorines also contributes 7 electrons. Additionally, there is one extra electron due to the negative charge.
- Total Valence Electrons: 7+(4×7)+1=367 + (4 \times 7) + 1 = 36.
- Bond Formation: Bromine forms single bonds with the four chlorines, which use up 4×2=84 \times 2 = 8 electrons for bonding. This leaves 36−8=2836 – 8 = 28 electrons.
- Lone Pairs: The remaining electrons are distributed as lone pairs. Each chlorine gets 3 lone pairs (4×6=244 \times 6 = 24), leaving 4 electrons, which are placed as 2 lone pairs on the bromine atom.
The Lewis structure shows Br in the center with four single bonds to Cl and two lone pairs on Br.
2. Molecular Geometry:
- The electron domain geometry for 6 regions of electron density (4 bonding pairs + 2 lone pairs) is octahedral.
- However, the two lone pairs occupy axial positions to minimize electron repulsion, leaving the four chlorine atoms in a square planar arrangement.
3. Hybridization:
- Bromine forms 6 orbitals to accommodate the 4 bonds and 2 lone pairs.
- This requires the mixing of one ss, three pp, and two dd orbitals, leading to sp³d² hybridization.
Summary:
The molecular shape of BrCl₄⁻ is square planar, and the hybridization of the central bromine atom is sp³d².