Which of the following is the correct Lewis structure for OSF4, ensuring that the formal charges of all atoms are zero?

• A. S is the central atom with one double bond to O and four single bonds to F, with lone pairs on O and S.
• B. S is the central atom with one single bond to O and four single bonds to F, with lone pairs on O and S.
• C. S is the central atom with one single bond to O and four single bonds to F, with lone pairs only on O.
• D. S is the central atom with one double bond to O and four double bonds to F, with lone pairs on O and S.

Answer: (A)

Verified step by step guidance

1. Identify the central atom in the molecule OSF4. Typically, the least electronegative atom is chosen as the central atom, which in this case is sulfur (S).
2. Determine the total number of valence electrons available. Oxygen (O) has 6 valence electrons, sulfur (S) has 6, and each fluorine (F) has 7. Calculate the total: 6 (O) + 6 (S) + 4 * 7 (F) = 40 valence electrons.
3. Arrange the atoms with sulfur in the center, bonded to oxygen and four fluorine atoms. Initially, connect each atom with a single bond, which uses up 10 electrons (5 bonds x 2 electrons per bond).
4. Distribute the remaining electrons to satisfy the octet rule, starting with the outer atoms (fluorine and oxygen). Each fluorine needs 6 more electrons to complete its octet, using up 24 electrons (4 F x 6 electrons). Oxygen will need 4 more electrons to complete its octet, using up the remaining 6 electrons.
5. Check the formal charges to ensure they are zero. Adjust the bonds if necessary. For sulfur to have a formal charge of zero, it should have a double bond with oxygen, as sulfur can expand its octet. This configuration will ensure all atoms have a formal charge of zero.