Determine the Lewis & VSEPR structure for ClO2F and determine if the molecule is polar
The Correct Answer and Explanation is:
The molecule ClO2F consists of a chlorine (Cl) atom bonded to two oxygen (O) atoms and one fluorine (F) atom. To determine the Lewis structure, we need to follow these steps:
1. Counting Valence Electrons:
- Chlorine (Cl) is in Group 17, so it has 7 valence electrons.
- Oxygen (O) is in Group 16, so each oxygen atom has 6 valence electrons. Since there are two oxygen atoms, we have 12 valence electrons from oxygen.
- Fluorine (F) is also in Group 17, so it has 7 valence electrons.
Thus, the total number of valence electrons is:
7(Cl)+12(O)+7(F)=26 valence electrons.7 (\text{Cl}) + 12 (\text{O}) + 7 (\text{F}) = 26 \text{ valence electrons.}7(Cl)+12(O)+7(F)=26 valence electrons.
2. Drawing the Lewis Structure:
- Chlorine will be the central atom since it is less electronegative than oxygen and fluorine.
- The two oxygen atoms and one fluorine atom will each form a single bond with chlorine.
- After the bonds, distribute the remaining electrons to complete the octet of oxygen and fluorine atoms.
- Chlorine, as a larger atom, will have more than 8 electrons around it in this case, which is allowed.
After arranging the atoms and distributing the electrons, the Lewis structure will look like this:
- Cl is single-bonded to each oxygen and fluorine.
- The oxygen atoms will have lone pairs to satisfy their octets.
- Fluorine will also have lone pairs.
3. VSEPR Structure:
The VSEPR theory helps predict the molecular geometry by considering the regions of electron density around the central atom. In ClO2F, there are three regions of electron density around chlorine: two from the oxygen atoms and one from the fluorine atom.
- Electron Domain Geometry: Trigonal planar.
- Molecular Geometry: The three bonded atoms create a trigonal pyramidal shape since the lone pairs on oxygen atoms are not part of the molecular shape.
4. Polarity:
To determine if ClO2F is polar, consider the electronegativity of the atoms and the molecular shape:
- Chlorine is less electronegative than fluorine but more electronegative than oxygen.
- The presence of fluorine, which is highly electronegative, creates a region of negative charge near it.
- The molecule has an asymmetrical shape (trigonal pyramidal), which means the dipoles from the different bonds do not cancel out.
Thus, ClO2F is a polar molecule because of its asymmetrical shape and the differences in electronegativity between the atoms, which result in a net dipole moment.
In summary:
- Lewis structure: Cl with single bonds to two oxygens and one fluorine, with lone pairs on oxygen and fluorine atoms.
- VSEPR geometry: Trigonal pyramidal.
- Polarity: The molecule is polar due to its asymmetric shape and electronegativity differences.
