Determine the mass of sulfur that reacts without residue with iron filings weighing 2.8 kg

Determine the mass of sulfur that reacts without residue with iron filings weighing 2.8 kg if in this case the chemical elements Fe and S are combined in mass ratios of 7: 4

Given:
m (Fe): m (S) = 7: 4
m (Fe) = 2.8 kg

Find:
m (S) -?

Solution:
1) Find the mass of the substance S:
To do this, it is necessary to make a proportion: if 7 parts of Fe react with 4 parts of S, then 2.8 kg of Fe react with (x) kg of S;
7 – 4
2.8 – x
x = 2.8 * 4/7 = 1.6;

m (S) = x = 1.6 kg.

Answer: The mass S is 1.6 kg.