What is the molecular shape of OCl2
a) trigonal planar
b) trigonal pyramidal
c) linear
d) angular
e) tetrahedral
The Correct Answer and Explanation is :
The correct molecular shape of OCl₂ (oxygen dichloride) is angular (option d).
Explanation:
To determine the molecular shape of a molecule like OCl₂, we need to consider the valence shell electron pair repulsion (VSEPR) theory, which helps predict the arrangement of atoms and lone pairs around a central atom.
- Electron Configuration of Oxygen:
- Oxygen (O) has 6 valence electrons, and each chlorine (Cl) atom has 7 valence electrons.
- When forming OCl₂, oxygen shares electrons with two chlorine atoms, resulting in two single bonds (O-Cl). This uses up two of oxygen’s valence electrons, leaving four electrons in the form of two lone pairs on the oxygen atom.
- Electron Domain:
- Oxygen in OCl₂ has two bonding pairs of electrons (from the O-Cl bonds) and two lone pairs of electrons.
- The total number of electron pairs around the oxygen atom is therefore 4 (2 bonding + 2 lone pairs).
- Electron Geometry:
- With 4 electron pairs, the electron geometry around the oxygen atom is tetrahedral. This is based on the fact that the electron pairs want to be as far apart as possible to minimize repulsion, forming a tetrahedral arrangement.
- Molecular Geometry:
- However, the molecular geometry describes only the arrangement of atoms, not the lone pairs.
- The presence of two lone pairs on oxygen will cause the molecule to adopt an angular (or bent) shape, which is similar to the geometry seen in water (H₂O), where two lone pairs also push the hydrogen atoms closer together.
- The bond angle in OCl₂ is less than 109.5° due to the repulsion from the lone pairs.
Thus, OCl₂ adopts an angular molecular shape, with a tetrahedral electron geometry. The correct answer is d) angular.