Final answer:
The formal charge on an oxygen atom that has six valence electrons, engages in three bonds, and has one lone pair is computed as +1. Calculating formal charges involves the subtraction of bonding and non-bonding electrons from the total valence electrons. The sum of the formal charges should match the total charge of the molecule.
Step-by-step explanation:
The student's question involves assigning a formal charge to an oxygen atom in a molecule. To calculate the formal charge on oxygen, we can use the formula:
Fc = Ve - (B + Nb), where:
Fc is the formal charge,
Ve is the number of valence electrons for oxygen (which is 6),
B is the number of bonds oxygen is participating in,
Nb is the number of nonbonding electrons on oxygen.
In this case, if the oxygen has three bonds and one lone pair, as mentioned, the calculation is:
Fc = 6 - (3 + 2) = +1
So the oxygen atom would have a +1 formal charge. Note that if the oxygen were part of a molecule with a negative charge, this calculation could vary depending on the overall charge distribution.
It is also important to remember that the sum of the formal charges in a molecule or ion should equal the total charge on the molecule or ion. For instance, if the molecule has a -2 charge overall, and oxygen atoms are each assigned a -1 charge, sulfur would have a +2 charge to balance it out.