To determine the properties of the nitrate ion (NO3–), we need to analyze various aspects:
A. Electron Geometry
The electron geometry is based on the arrangement of electron groups around the central nitrogen atom. In NO3–, the nitrogen atom is surrounded by three oxygen atoms and has a formal negative charge. This results in four regions of electron density (three bonding pairs and one lone pair) which corresponds to a tetrahedral electron geometry.
B. Molecular Geometry Shape
When we focus solely on the arrangement of the atoms (not the lone pairs), we consider that the lone pair on nitrogen does not influence the molecular shape directly, resulting in a trigonal planar geometry for the nitrate ion. This shape accommodates the three oxygen atoms symmetrically around the nitrogen atom.
C. Is the Molecule Symmetrical or Asymmetrical?
The molecular geometry of NO3– is trigonal planar, which is a symmetrical shape. The three oxygen atoms are arranged evenly around the nitrogen atom, leading to a balanced distribution of charge. Therefore, this molecule is considered symmetrical.
D. Is the Molecule Polar or Nonpolar?
Despite the presence of polar bonds between nitrogen and oxygen, the symmetrical arrangement of the NO3– molecule means that the dipole moments cancel each other out. As a result, NO3– is a nonpolar molecule overall.
In summary, for the nitrate ion (NO3–), the properties are as follows:
- Electron Geometry: Tetrahedral
- Molecular Geometry Shape: Trigonal Planar
- Symmetrical or Asymmetrical: Symmetrical
- Polar or Nonpolar: Nonpolar