Question

Cl-C-Cl bond angle in ${\mathrm{CCl}}_4$ is

Short answer

Answer: The Cl-C-Cl bond angle in a CCl₄ molecule is approximately 109.5°.

Step-by-step solution

Determine the number of bonding and electron pairs.

The central carbon atom is sharing a single bond with each of the four chlorine atoms, making it a total of 4 bonding pairs. There are no other unshared electron pairs (lone pairs) around the central carbon atom in ${\mathrm{CCl}}_4$.

Identify the molecular geometry.

Based on the 4 bonding pairs and 0 lone pairs, we can identify the molecular geometry as tetrahedral. In a tetrahedral molecular geometry, the central atom is surrounded by 4 atoms at the vertices of a tetrahedron.

Determine the Cl-C-Cl bond angle.

In a tetrahedral molecule, any two bonded atoms (vertex atoms) and the central atom form an angle of approximately 109.5°. So, the Cl-C-Cl bond angle in ${\mathrm{CCl}}_4$ is approximately 109.5°.

Key concepts

Bonding Pairs

In chemistry, bonding pairs refer to the shared pairs of electrons between atoms in a molecule. These shared electrons form a covalent bond, holding the atoms together. In the case of ${\mathrm{CCl}}_4$, the carbon atom forms single covalent bonds with each of the four chlorine atoms. This results in a total of four bonding pairs. These electrons are crucial as they allow atoms to achieve stable electron configurations. When analyzing molecular structures, identifying the number of bonding pairs helps predict the molecule's geometry and properties.

Lone Pairs

Lone pairs are pairs of valence electrons that are not involved in bonding and remain localized on a single atom. In ${\mathrm{CCl}}_4$, the central carbon atom has no lone pairs, as all its valence electrons are used for bonding with chlorine atoms. Lone pairs can influence molecular geometry by affecting bond angles and potentially causing deviations from ideal geometries. However, in ${\mathrm{CCl}}_4$, the absence of lone pairs allows the bonding pairs to arrange themselves symmetrically around the carbon atom.

Cl-C-Cl Bond Angle

The Cl-C-Cl bond angle refers to the angle formed between two chlorine atoms bonded to the same carbon atom in ${\mathrm{CCl}}_4$. In tetrahedral geometries, such as in this molecule, the bond angle is approximately ${109.5}^{\circ }$. This angle is derived from the symmetrical arrangement of bonding pairs, optimizing the spatial distribution of electron density and minimizing electron pair repulsion. Recognizing this bond angle helps in understanding the shape and spatial arrangement of the molecule.

Molecular Geometry in Chemistry

Molecular geometry describes the three-dimensional arrangement of atoms in a molecule. It is essential for predicting physical and chemical properties. The tetrahedral geometry seen in ${\mathrm{CCl}}_4$ arises from the four bonding pairs with no lone pairs on the central carbon. Tetrahedral is one of several molecular geometries determined using VSEPR (Valence Shell Electron Pair Repulsion) theory. Understanding this concept helps chemists visualize molecules, anticipate reactivity, and design compounds with specific functions, making it a cornerstone of molecular chemistry.