Determine the electron geometry, molecular geometry, and idealized bond angles for each molecule. In which cases do you expect deviations from the idealized bond angle?
a. CS2
b. SCl2
c. CHF3
d. PF3

Verified step by step guidance

1. <b>Step 1:</b> Determine the electron geometry for each molecule by considering the number of electron groups around the central atom. Use VSEPR theory to predict the arrangement of these groups.
2. <b>Step 2:</b> Determine the molecular geometry by considering the number of bonding pairs and lone pairs on the central atom. The molecular geometry is derived from the electron geometry but considers only the positions of the atoms.
3. <b>Step 3:</b> Identify the idealized bond angles for each molecular geometry. For example, linear geometries have bond angles of 180°, trigonal planar have 120°, tetrahedral have 109.5°, etc.
4. <b>Step 4:</b> Analyze each molecule to determine if there are any factors that might cause deviations from the idealized bond angles. Factors include the presence of lone pairs or differences in electronegativity between atoms.
5. <b>Step 5:</b> For each molecule, summarize the electron geometry, molecular geometry, idealized bond angles, and any expected deviations from these angles.

Key Concepts

VSEPR Theory

Valence Shell Electron Pair Repulsion (VSEPR) Theory is a model used to predict the geometry of individual molecules based on the repulsion between electron pairs in the valence shell of the central atom. According to this theory, electron pairs will arrange themselves as far apart as possible to minimize repulsion, leading to specific molecular shapes and bond angles.

Molecular Geometry vs. Electron Geometry

Molecular geometry refers to the three-dimensional arrangement of atoms in a molecule, while electron geometry considers the spatial arrangement of all electron pairs, including lone pairs. The presence of lone pairs can alter the observed molecular geometry, leading to differences between the idealized electron geometry and the actual molecular shape.

Idealized Bond Angles

Idealized bond angles are the angles between adjacent bonds in a molecule as predicted by VSEPR theory for a given electron geometry. However, these angles can deviate due to factors such as lone pair repulsion, differences in atom sizes, and electronegativity, which can affect the distribution of electron density and thus the angles between bonds.