What is the electronic geometry and bond angles for PCl5?

In phosphorus pentachloride (PCl5), the phosphorus atom is surrounded by five chlorine atoms, leading to a total of five bonding pairs of electrons. The presence of these five bonds determines the molecule's electronic geometry.

According to VSEPR (Valence Shell Electron Pair Repulsion) theory, the most stable arrangement for five electron pairs is trigonal bipyramidal. This geometry features two different types of bond angles: the axial bonds (which are aligned vertically) are at 90° to the equatorial bonds (which are arranged horizontally), while the equatorial bonds are 120° apart from each other. In this configuration, there are two axial positions and three equatorial positions.

Thus, the correct description of the electronic geometry for PCl5 is trigonal bipyramidal, with bond angles of 90° between axial and equatorial bonds, and 120° between the equatorial bonds. This understanding of molecular geometry is fundamental in predicting and explaining the behavior of molecules in chemical reactions and interactions.