AlF3 Molecular Geometry, Bond Angles & Electron Geometry

An explanation of the molecular geometry for the AlF3 (Aluminum fluoride) including a description of the AlF3 bond angles. The electron geometry for the Aluminum fluoride is also provided. The ideal bond angle for the Aluminum fluoride is 120° since it has a Trigonal planer molecular geometry. Experimentally we would expect the bond angle to be approximately 120°. To determine the molecular geometry, or shape for a compound like AlF3, we complete the following steps: 1) Draw the Lewis Structure for the compound. 2) Predict how the atoms and lone pairs will spread out when the repel each other. 3) Use a chart based on steric number (like the one in the video) or use the AXN notation to find the molecular shape. This will be determined by the number of atoms and lone pairs attached to the central atom. If you are trying to find the electron geometry for AlF3 we would expect it to be Trigonal planer. Helpful Resources: Drawing/writing done in InkScape. Screen capture done with Camtasia Studio 4.0. Done on a Dell Dimension laptop computer with a Wacom digital tablet (Bamboo).