Give the geometry and approximate bond angles around the central atom in CCl3-. (LO 8.1) (a) Trigonal planar, 120° (b) Trigonal pyramidal, 109.5° (c) Trigonal pyramidal, 120° (d) Bent, 109.5°

Verified step by step guidance

1. Identify the central atom in the molecule CCl3-. In this case, the central atom is Carbon (C).
2. Determine the number of electron groups around the central atom. This includes both bonding pairs and lone pairs. Carbon in CCl3- forms three bonds with Chlorine atoms and has one lone pair.
3. Use the VSEPR (Valence Shell Electron Pair Repulsion) theory to predict the molecular geometry. According to VSEPR, electron groups around the central atom will arrange themselves to minimize repulsion.
4. Recognize that with three bonding pairs and one lone pair, the molecular geometry will be trigonal pyramidal.
5. Determine the approximate bond angles. In a trigonal pyramidal geometry, the bond angles are approximately 109.5°.

Key Concepts

VSEPR Theory

Valence Shell Electron Pair Repulsion (VSEPR) Theory is a model used to predict the geometry of molecules based on the repulsion between electron pairs around a central atom. According to this theory, electron pairs, whether bonding or lone pairs, will arrange themselves to minimize repulsion, leading to specific molecular shapes.

Molecular Geometry

Molecular geometry refers to the three-dimensional arrangement of atoms in a molecule. It is determined by the number of bonding pairs and lone pairs of electrons around the central atom, which influences the overall shape and bond angles. For example, a central atom with three bonding pairs and one lone pair typically adopts a trigonal pyramidal shape.

Bond Angles

Bond angles are the angles formed between adjacent bonds in a molecule. They are influenced by the molecular geometry and the presence of lone pairs, which can compress or expand the angles between bonding pairs. For instance, in a trigonal pyramidal geometry, the bond angles are approximately 107° due to the repulsion from the lone pair.