Question

Iron and sulfur react to yield iron sulfide. Balance this reaction.

a. 8 Fe(s) + 8 S8(s) → 8 FeS(s)
b. Fe(s) + S8(s) → FeS(s)
c. 8 Fe(s) + S8(s) → 8 FeS(s)
d. 8 Fe(s) + 8 S8(s) → FeS(s)

Answer 1

The balanced equation for the reaction of iron with sulfur to form iron sulfide is 8 Fe(s) + 8 S8(s) → 8 FeS(s), which indicates a one-to-one molar ratio between iron, sulfur, and iron sulfide.

Step-by-step explanation:

To balance the reaction between iron (Fe) and sulfur (S) to form iron sulfide (FeS), we start by counting the number of atoms of each element on both the reactant side and the product side of the equation. For the given options, the correctly balanced equation is:

Fe(s) + S(s) → FeS(s)

This implies that one atom of iron reacts with one atom of sulfur to yield one formula unit of iron sulfide. This can also be represented as:

8 Fe(s) + 8 S8(s) → 8 FeS(s)

where each S8 represents an eight-atom ring of sulfur, which is common in elemental sulfur's crystalline form, and we have used the empirical formula of sulfur as S. Note: The option 'a' is correct because it represents that one mole of iron reacts with one mole of sulfur to produce one mole of iron sulfide, and for stoichiometric balance, all coefficients must be equal if they are expressed in moles in a balanced chemical reaction.