Arsenic Tribromide Shape

Arsenic tribromide (AsBr3) is a chemical compound consisting of one arsenic atom and three bromine atoms. The shape of AsBr3 can be determined using the Valence Shell Electron Pair Repulsion (VSEPR) theory, which predicts molecular geometry based on the repulsion between valence electron pairs.

In AsBr3, the central arsenic atom has a total of five valence electrons - three from the bromine atoms and two from its own outer shell. These five valence electrons are distributed around the arsenic atom in a trigonal bipyramidal arrangement.

The VSEPR theory predicts that the arrangement of these valence electron pairs will push each other as far apart as possible, creating specific bond angles between them. In a trigonal bipyramidal arrangement, there are three equatorial positions and two axial positions.

The three bromine atoms occupy the equatorial positions, while the two lone pairs of electrons on the arsenic atom occupy the axial positions. The bond angles between the equatorial bromine atoms are 120 degrees, while the bond angles between the axial lone pairs and the equatorial bromine atoms are 90 degrees.

Therefore, the shape of AsBr3 is trigonal bipyramidal, with the three bromine atoms arranged in a plane at the equator, and the two lone pairs of electrons on the arsenic atom extending in opposite directions along the axis perpendicular to the plane.