Question

What is the mass of sulphur that would react with 5 g of iron to form ferrous sulphide $\left(FeS\right)$?

• A. 3.2 g
• B. 2.85 g
• C. 5.7 g
• D. 5.9 g

Answer 1

The correct option is B

2.85 g

• In the formation of FeS, the mass ratio of iron to sulphur is 1:1; which means 56 g of iron combines with 32 g of sulphur to form ferrous sulphide.

(Gram atomic mass of iron = 56 g, Gram atomic mass of sulphur = 32 g)

• Accordingly, 5 grams of iron will combine with $\frac{5\times 32}{56}$g = 2.85 g of sulphur.
• So, 2.85 g of sulphur would react with 5 g of iron to form FeS.