For the following molecules or ions, provide a Lewis dot structure. b. Hybridization around the central atom. c. Angles. d. Electronic geometry. e. Molecular geometry. f. Polarity. (H2O) +1 OF2 (IO2F2)-1 BrF2 XeF2A (BF4)-1 (NO2) +1 (IF2)-1 XeOF4 SO2Cl2
The Correct Answer and Explanation is:
. (H₂O)⁺
- Lewis Structure: O bonded to two H atoms, 1 lone pair on O (since it’s positively charged, one electron is lost).
- Hybridization: sp²
- Bond Angles: ~120°
- Electronic Geometry: Trigonal planar
- Molecular Geometry: Bent
- Polarity: Polar
2. OF₂ (Oxygen Difluoride)
- Lewis Structure: O in the center with two single bonds to F atoms, and 2 lone pairs on O.
- Hybridization: sp³
- Bond Angles: ~103°
- Electronic Geometry: Tetrahedral
- Molecular Geometry: Bent
- Polarity: Polar
3. (IO₂F₂)⁻
- Lewis Structure: Iodine central atom bonded to 2 O and 2 F atoms, 1 lone pair on I. Formal charges adjusted for -1.
- Hybridization: sp³d
- Bond Angles: ~90°, 120°
- Electronic Geometry: Trigonal bipyramidal
- Molecular Geometry: See-saw
- Polarity: Polar
4. BrF₂
- Lewis Structure: Br central atom, 2 F atoms bonded, 3 lone pairs on Br.
- Hybridization: sp³d
- Bond Angles: ~180°
- Electronic Geometry: Trigonal bipyramidal
- Molecular Geometry: Linear
- Polarity: Nonpolar
5. XeF₂
- Lewis Structure: Xe central atom, 2 F atoms bonded, 3 lone pairs on Xe.
- Hybridization: sp³d
- Bond Angles: 180°
- Electronic Geometry: Trigonal bipyramidal
- Molecular Geometry: Linear
- Polarity: Nonpolar
6. (BF₄)⁻
- Lewis Structure: B central atom with four single bonds to F atoms, no lone pairs on B, extra electron gives -1 charge.
- Hybridization: sp³
- Bond Angles: 109.5°
- Electronic Geometry: Tetrahedral
- Molecular Geometry: Tetrahedral
- Polarity: Nonpolar
7. (NO₂)⁺
- Lewis Structure: N double bonded to one O, single bonded to another O⁺, with resonance.
- Hybridization: sp²
- Bond Angles: ~120°
- Electronic Geometry: Trigonal planar
- Molecular Geometry: Bent
- Polarity: Polar
8. (IF₂)⁻
- Lewis Structure: Iodine bonded to 2 F atoms, 3 lone pairs on I.
- Hybridization: sp³d
- Bond Angles: ~180°
- Electronic Geometry: Trigonal bipyramidal
- Molecular Geometry: Linear
- Polarity: Nonpolar
9. XeOF₄
- Lewis Structure: Xe central, bonded to 4 F atoms and 1 O (double bond), 1 lone pair on Xe.
- Hybridization: sp³d²
- Bond Angles: ~90°, 180°
- Electronic Geometry: Octahedral
- Molecular Geometry: Square pyramidal
- Polarity: Polar
10. SO₂Cl₂ (Thionyl chloride)
- Lewis Structure: S in the center with 2 double bonds to O and single bonds to 2 Cl atoms.
- Hybridization: sp³
- Bond Angles: ~109.5°
- Electronic Geometry: Tetrahedral
- Molecular Geometry: Tetrahedral
- Polarity: Polar
Explanation:
Molecular geometry and polarity are crucial in understanding chemical behavior. The Lewis structure serves as the foundation, revealing electron arrangement. Hybridization explains how atomic orbitals mix to form bonds, determining geometry. For instance, sp³ hybridization leads to a tetrahedral geometry with ~109.5° angles, seen in molecules like (BF₄)⁻ and SO₂Cl₂. Deviations occur when lone pairs are present, causing repulsion and bent shapes, as seen in OF₂ or (H₂O)⁺.
Trigonal planar structures like (NO₂)⁺ result from sp² hybridization, with 120° angles, whereas linear geometries like XeF₂ arise from sp³d hybridization but involve lone pairs occupying equatorial positions to minimize repulsion. In larger molecules like XeOF₄, sp³d² hybridization leads to octahedral electron geometries, and lone pairs modify molecular shape, making it square pyramidal.
Polarity depends on both geometry and bond dipoles. Nonpolar molecules, such as XeF₂ or BrF₂, have symmetrical geometries that cancel dipoles. In contrast, polar molecules like OF₂ and XeOF₄ lack symmetry, leading to a net dipole.
In summary, analyzing Lewis structures, hybridization, and geometries allows prediction of molecular behavior. This understanding is fundamental in predicting reactivity, solubility, and intermolecular interactions.
