During the interaction of iron (III) hydroxide with hydrochloric acid, a salt with a mass of 48.75 g was formed.

During the interaction of iron (III) hydroxide with hydrochloric acid, a salt with a mass of 48.75 g was formed. Find the mass of hydrochloric acid with a mass fraction of hydrogen chloride of 10% required for the reaction.

To solve the problem, we write down the reaction equation:
Fe (OH) 3 + 3HCl = FeCl3 + 3H2O
Accordingly, 48.75 g of iron (III) chloride was formed. Let’s find its quantity by the formula n = m / M
n (FeCl3) = 48.75 / 162.5 = 0.3 mol
Based on the reaction equation, n (HCl) = 3n (FeCl3) = 0.9 mol. Then 0.9 mol of pure hydrogen chloride reacted, we find its mass:
m (HCl) = 0.9 * 36.5 = 32.85 g
Since the initial substance is a solution, its mass can be found by the formula m (p) = m (p.p.) / W
m (p) = 32.85 / 0.1 = 328.5 g