What is the chemical formula for lead(IV) sulfide?

The correct chemical formula for lead(IV) sulfide is indeed PbS2. In this compound, lead is in the +4 oxidation state, as indicated by the Roman numeral IV in its name. Sulfur typically has a -2 oxidation state.

To achieve electrical neutrality in the compound, the total positive charge from lead must balance the total negative charge from sulfur. Since one lead ion contributes a +4 charge, two sulfide ions (each with a -2 charge) are required to balance it out. This results in:

[ +4 , \text{(from Pb)} + (-2) + (-2) , \text{(from 2 S)} = 0 ]

Thus, the presence of two sulfur atoms leads to the formula PbS2, where lead(IV) sulfide is formed with one lead ion and two sulfide ions.