Find a mass of iron that can react with 200 g of a 19.6% sulfuric acid solution.

Let us write the equation for the reaction of the interaction of iron and dilute sulfuric acid:
Fe + H2SO4 = FeSO4 + H2
Determine the mass of pure acid, through the mass fraction of the substance in the solution:
w (in-va) = (m (in-va) / m (solution)) * 100%
m (in-va) = w (in-va) * m (solution) / 100
m (in-va) = 19.6 * 200/100 = 39.2 g
According to the law of conservation of matter by reaction, we get:
m (Fe) / M (Fe) = m (H2SO4) / M (H2SO4)
Let’s define the molar masses:
M (H2SO4) = 1 * 2 + 32 + 16 * 4 = 98 g / mol
M (Fe) = 56 g / mol
Determine the mass of iron:
m (Fe) = m (H2SO4) * M (Fe) / M (H2SO4)
m (Fe) = 39.2 * 56/98 = 22.4 g
Answer: a given amount of acid will react with iron weighing 22.4 g.