VSEPR

• VSEPR Theory


  (Valence-Shell Electron-Pair Repulsion) This is used to predict 3D molecular geometry of molecules and ions using the number of valence electrons and bond pairs
• Steps in using the VSEPR chart to determine the molecular geometry of covalent compounds

  1. Draw the LEDs of the given covalent compound (Arrange the bond pairs and lone pairs properly based on past lectures)

  2. Count the bond pairs and lone pairs of the central atom

  3. In the VSEPR Chart, look for the bond-lone pairs combination to determine the proposed shapes of the covalent compound

  4. Draw the skeletal model and 3D model based on the VSEPR chart

  5. Identify the parent and molecular shapes
• Molecular geometry examples


  • (Various molecular geometry diagrams)
• No need to draw the lone pairs of peripheral atoms in writing the skeletal and 3D model
• Always follow the VSEPR chart on how the angles are arranged. Do not invent your own geometrical shapes
• Double bond and triple bond are counted as 1 bond pair in terms of the VSEPR theory
• If the covalent bond has triple or double bond, always show these in your skeletal and 3D models
• For diatomic molecules like O2, N2, F2, etc., there is no need to count for the bond and lone pairs—they are categorized under linear geometrical shape
• VSEPR Chart


  • (Diagram showing VSEPR chart)