How much H2 will react with iron oxide 3 with a mass of 40g.

Let us find the amount of the substance of iron oxide Fe2O3 by the formula:

n = m: M.

M (Fe2O3) = 160 g / mol.

n = 40 g: 160 g / mol = 0.25 mol.

Let’s find the quantitative ratios of substances.

Fe2O3 + 3H2 → 2Fe + 3H2O

There is 3 mol of H2 per 1 mol of Fe2O3.

The substances are in quantitative ratios of 1: 3.

The amount of hydrogen is 3 times more than the amount of Fe2O3.

n (H2) = 3n (Fe2O3) = 0.25 × 3 = 0.75 mol.

Let’s find the volume of H2.

V = Vn n, where Vn is the molar volume of gas, equal to 22.4 l / mol, and n is the amount of substance.

V = 0.75 mol × 22.4 L / mol = 16.8 L.

Answer: 16.8 liters.