Determine the geometry about each interior atom in each molecule and sketch the molecule. (Skeletal structure is indicated in parentheses.)
a. CH₃NH₂ (H₃CNH₂)
b. CH₃CO₂CH₃ (H₃CCOOCH₃ One O atom attached to 2nd C atom; the other O atom is bonded to the 2nd and 3rd C atom)

Key Concepts

Molecular Geometry

Molecular geometry refers to the three-dimensional arrangement of atoms within a molecule. It is determined by the number of bonding pairs and lone pairs of electrons around the central atom, which influences the shape of the molecule. Common geometries include linear, trigonal planar, tetrahedral, and bent, each resulting from specific arrangements of electron pairs according to VSEPR (Valence Shell Electron Pair Repulsion) theory.

VSEPR Theory

VSEPR theory is a model used to predict the geometry of individual molecules based on the repulsion between electron pairs surrounding a central atom. According to this theory, electron pairs will arrange themselves as far apart as possible to minimize repulsion, leading to specific molecular shapes. Understanding VSEPR is crucial for determining the spatial arrangement of atoms in a molecule, which directly affects its properties and reactivity.

Skeletal Structure

A skeletal structure is a simplified representation of a molecule that shows the connectivity between atoms without depicting all the hydrogen atoms explicitly. In skeletal formulas, carbon atoms are represented by vertices or ends of lines, while other atoms, such as oxygen, are shown as letters. This notation helps chemists quickly visualize the molecular framework and is particularly useful for larger organic molecules, facilitating the identification of functional groups and overall structure.