Silicon tetrachloride (SiCl4) is a chemical compound formed by one silicon atom and four chlorine atoms. To predict its molecular shape, we can employ the Valence Shell Electron Pair Repulsion (VSEPR) theory.
According to VSEPR theory, the shape of a molecule is determined by the arrangement of its bonding and non-bonding electron pairs around the central atom. In the case of SiCl4, silicon is the central atom surrounded by four chlorine atoms. Silicon has four valence electrons, and each chlorine atom contributes one electron for a total of four shared pairs of electrons.
Since there are no lone pairs on the silicon atom and four bonding pairs, we can determine the geometry by focusing on these bonding pairs. The arrangement of four electron pairs around a central atom adopts a tetrahedral geometry to minimize the repulsion between the pairs.
In a tetrahedral structure, the bond angles between the chlorine atoms are approximately 109.5 degrees, creating a symmetrical shape. As a result, silicon tetrachloride has a tetrahedral molecular geometry.
In conclusion, using VSEPR theory, we predict that the shape of silicon tetrachloride (SiCl4) is tetrahedral.