Calculate the mass of a 10% hydrochloric acid solution that is required to completely dissolve 21.4 g

Calculate the mass of a 10% hydrochloric acid solution that is required to completely dissolve 21.4 g of iron hydroxide (3).

1. Let’s write down the equality of chemical interaction:

Fe (OH) 3 + 3HCl = FeCl3 + 3H2O.

2. Find the chemical number of iron hydroxide:

n (Fe (OH) 3) = m (Fe (OH) 3) / M (Fe (OH) 3) = 21.4 g / 107 g / mol = 0.2 mol.

3. Based on the equality of the chemical interaction, we find the chemical number and, as a result, the mass of hydrochloric acid:

n (HCl) = n (Fe (OH) 3) * 3 = 0.2 mol * 3 = 0.6 mol.

m (HCl) = n (HCl) * M (HCl) = 0.6 mol * 36.5 g / mol = 21.9 g.

4. Calculate the mass of the hydrochloric acid solution:

m (solution) = m (HCl) * 100% / ω (HCl) = 21.9 g * 100% / 10% = 219 g.

Answer: m (solution) = 219 g.