Skip to main content
Ch.8 - Covalent Compounds: Bonding Theories and Molecular Structure
Chapter 8, Problem 53

A potential replacement for the chlorofluorocarbon refrigerants that harm the Earth's protective ozone layer is a compound called E143a, or trifluoromethyl methyl ether, F3COCH3. Draw an electron-dot structure for F3COCH3, and predict the geometry around both the carbons and the oxygen.

Verified step by step guidance
1
Identify the total number of valence electrons in the molecule F3COCH3. Carbon has 4 valence electrons, oxygen has 6, and fluorine has 7. Remember to count each atom's electrons and add them together.
Draw a skeletal structure for F3COCH3. Connect the central carbon atom to the oxygen atom and the other carbon atom. Then, attach the three fluorine atoms to the oxygen atom.
Complete the octets around the atoms by adding lone pairs. Oxygen and fluorine atoms should each have a complete octet.
Use the VSEPR theory to predict the geometry around each carbon atom and the oxygen atom. For the central carbon, consider the arrangement of the single bonds and any lone pairs. For the oxygen, consider its bonds with fluorine and carbon.
Determine the molecular geometry around each atom based on the number of bonding pairs and lone pairs. This will help in predicting the shape of the molecule.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Electron-Dot Structures

Electron-dot structures, also known as Lewis structures, represent the valence electrons of atoms within a molecule. They illustrate how atoms are bonded together and show the arrangement of electrons, including lone pairs. Understanding how to draw these structures is essential for predicting molecular geometry and reactivity.
Recommended video:
Guided course
04:28
Lewis Dot Structures: Ions

VSEPR Theory

Valence Shell Electron Pair Repulsion (VSEPR) theory is a model used to predict the geometry of molecules based on the repulsion between electron pairs surrounding a central atom. According to VSEPR, electron pairs will arrange themselves to minimize repulsion, leading to specific molecular shapes. This theory is crucial for determining the spatial arrangement of atoms in a molecule like trifluoromethyl methyl ether.
Recommended video:
Guided course
02:13
Molecular Shapes and VSEPR

Hybridization

Hybridization is the concept of mixing atomic orbitals to form new hybrid orbitals that can accommodate bonding in molecules. In the case of carbon and oxygen in F3COCH3, understanding hybridization helps predict the types of bonds formed and the geometry around each atom. For example, sp3 hybridization indicates tetrahedral geometry, while sp2 suggests trigonal planar arrangements.
Recommended video:
Guided course
00:51
Hybridization