Answer:
3S₈ + 28Br₂ => 8S₃Br₇
Step-by-step explanation:
Start with either sulfur (S) or bromine (Br) and balance ...
3S₈ + Br₂ => 8S₃Br₇ or S₈ + 7/2Br₂ => S₃Br₇
Balance the remaining reactant ...
3S₈ + 56/2Br₂ => 8S₃Br₇
Remove fractions by multiplying by the fraction's denominator
2(3S₈ + 56/2Br₂ => 8S₃Br₇) => 6S₈ + 56Br₂ => 16S₃Br₇
Reduce to smallest whole number ratio => standard equation at STP ...
3S₈ + 28Br₂ => 8S₃Br₇