CCl4, also known as carbon tetrachloride, has a molecular geometry that is tetrahedral. This means that the carbon atom is at the center, with four chlorine atoms symmetrically arranged around it at the corners of a tetrahedron.
The reason for this geometry lies in the concept of valence shell electron pair repulsion (VSEPR) theory. According to VSEPR theory, electron pairs around a central atom will arrange themselves in such a way as to minimize repulsion between them. In the case of CCl4, the carbon atom has four valence electrons, each of which forms a single bond with a chlorine atom. These four bonding pairs of electrons repel each other equally, leading to a tetrahedral arrangement where each bond angle is approximately 109.5 degrees.
This symmetrical arrangement not only minimizes electron pair repulsion but also results in a non-polar molecule, despite the polar nature of the C-Cl bonds. The dipole moments of the individual bonds cancel out due to the symmetrical geometry, making CCl4 a non-polar molecule overall.