What is the mass of the solution in which the mass fraction of sulfuric acid is 4.9% should be taken to dissolve 8.4 g of iron?

1. Let’s compose the equation for the reaction of iron with sulfuric acid:

Fe + H2SO4 = FeSO4 + H2 ↑;

2.Calculate the chemical amount of iron:

n (Fe) = m (Fe): M (Fe) = 8.4: 56 = 0.15 mol;

3. Determine the amount of reacted sulfuric acid:

n (H2SO4) = n (Fe) = 0.15 mol;

4.calculate the mass of the acid:

m (H2SO4) = n (H2SO4) * M (H2SO4);

M (H2SO4) = 2 + 32 + 4 * 16 = 98 g / mol;

m (H2SO4) = 0.15 * 98 = 14.7 g;

5. find the mass of the sulfuric acid solution:

m (solution) = m (H2SO4): w (H2SO4) = 14.7: 0.049 = 300 g.

Answer: 300 g.