To draw the Lewis structure for sulfur oxyfluoride (SOF4), we start by determining the total number of valence electrons available. Sulfur has 6 valence electrons, oxygen has 6, and each of the four fluorine atoms has 7. This gives us:
- Sulfur (S): 6 electrons
- Oxygen (O): 6 electrons
- Fluorine (F): 4 x 7 = 28 electrons
Adding these together results in:
Total valence electrons = 6 + 6 + 28 = 40
Next, we place sulfur at the center, surrounded by the four fluorine atoms and one oxygen atom. Fluorine atoms will be attached to sulfur with single bonds since fluorine is highly electronegative and prefers to form one bond. Oxygen will also be connected to sulfur, but we will consider making a double bond with oxygen to satisfy the valence requirement.
We proceed to distribute the electrons:
- Place the 4 pairs of electrons (8 electrons) for the single bonds between sulfur and each fluorine atom.
- This leaves us with 32 electrons.
- Assign a single bond between sulfur and oxygen with 2 electrons.
- Now we have 30 electrons left.
- With the remaining electrons, we complete the octet for each fluorine (6 electrons for each fluorine, totaling 24), which uses up 24 of the 30 remaining electrons. This leaves 6 electrons.
- Now, we can place the remaining 6 electrons around the oxygen, giving it a total of 4 lone pair electrons, while creating a double bond with sulfur.
Finally, we have the structure:
- Single bonds between sulfur and each fluorine with 3 lone pairs on each fluorine.
- A double bond between sulfur and oxygen with two lone pairs of electrons on oxygen.
This Lewis structure fulfills the octet rule for the surrounding elements while keeping sulfur stable with expanded octets due to its ability to hold more than 8 electrons.