What is PBr5 Lewis Structure?

The Lewis structure of phosphorus pentabromide (PBr₅) visually represents the bonding between phosphorus (P) and bromine (Br) atoms, as well as the lone pairs of electrons. In PBr₅, phosphorus acts as the central atom.

To construct the Lewis structure for PBr₅, follow these steps:

1. Count the total valence electrons: Phosphorus has 5 valence electrons, and each bromine has 7 valence electrons. Thus, the total is 5 + (5 × 7) = 40 valence electrons.
2. Determine the central atom: Phosphorus is less electronegative than bromine, making it the central atom.
3. Form bonds: Draw single bonds from the phosphorus atom to each of the five bromine atoms. Each bond uses 2 electrons, totaling 10 electrons (5 bonds).
4. Distribute remaining electrons: After bonding, 30 valence electrons remain. Each bromine atom needs 6 additional electrons to complete their octet, which utilizes all the remaining electrons.

The final structure shows phosphorus in the center with five bromine atoms surrounding it, forming single bonds. Each bromine atom has three lone pairs of electrons, while phosphorus has no lone pairs.

This results in a trigonal bipyramidal geometry for PBr₅, with bond angles of 90° and 120°.