Question

Determine the electron geometry (eg) and molecular geometry (mg) of CF3+. Show Lewis structure.

Answer 1

The
`\( CF_3^+ \)`ion has a central carbon atom with three fluorine atoms bonded to it and one positive charge indicating a missing electron. In terms of electron geometry (eg), the carbon atom originally has four areas of electron density (three from the fluorine atoms and one from the lone pair).

However, when it loses an electron and becomes positively charged, it has only three areas of electron density, which makes the geometry trigonal planar.

Since there is no lone pair on the carbon atom in the
`\( CF_3^+ \)` ion, the molecular geometry (mg) is the same as the electron geometry, which is also trigonal planar.

To show the Lewis structure for
`\( CF_3^+ \)`, you would draw the carbon in the center with three fluorine atoms around it, each bonded to the carbon with a single line representing a pair of shared electrons.

Each fluorine will have three pairs of dots representing the remaining six electrons that are not involved in bonding. The carbon will not have any lone pairs of electrons, indicating that it has given up one electron, hence the positive charge.

Answer 2

• Electron Geometry (EG): Trigonal Planar
• Molecular Geometry (MG): Trigonal Planar

Three fluorine atoms and a central carbon atom are joined to form the trifluoromethyl cation, or CF₃⁺. Both the molecular geometry (MG) and electron geometry (EG) have a total of 26 valence electrons, making them trigonal planar. This arrangement of three bonding pairs is symmetrical and results from the absence of lone pairs on the central carbon atom.

The overall structure of the CF₃⁺ molecule is characterized by its trigonal planar electron and molecular geometries, which represent the configuration of atoms and valence electrons in this cationic species.