To 5.6 g of iron was added 6.4 g of sulfur. Find the mass of ferrous sulfate.

Given:

m (Fe) = 5.6 g

m (S) = 6.4 g

To find:

m (FeS) -?

Decision:

Fe + S = FeS, – we solve the problem, relying on the composed reaction equation:

1) Find the amount of iron and sulfur:

n (Fe) = m: M = 5.6 g: 56 g / mol = 0.1 mol

n (S) = m: M = 6.4 g: 32 g / mol = 0.2 mol

We start from the smallest amount to get more accurate calculations, that is, we work with 0.1 mol.

2) We compose a logical expression:

If 1 mol of Fe gives 1 mol of FeS,

then 0.1 mol of Fe will give x mol of FeS,

then x = 0.1 mol.

3) Find the mass of iron sulfide formed during the reaction:

m (FeS) = n * M = 0.1 mol * 88 g / mol = 8.8 g.

Answer: m (FeS) = 8.8 g.