Final answer:
The correct chemical formulas for the given compounds are provided.
Step-by-step explanation:
Here are the correct electrically-neutral chemical formulas for the compounds:
a) Mercury(II) sulfite: HgSO3
b) Iron (III) phosphate: FePO4
c) Bromous acid: HBrO2
d) 3laggingstrand: This appears to be a typographical error or an incomplete question. Please provide the correct compound name for a proper formula.