Iron weighing 14 g reacted with chlorine. Find the mass of iron (III) chloride if the practical yield is 90%.

The equation for the reaction of iron with chlorine:

2Fe + 3Cl2 = 2FeCl3

The amount of iron substance:

v (Fe) = m (Fe) / M (Fe) = 14/56 = 0.25 (mol).

According to the reaction equation, 2 mol of FeCl3 is formed per 2 mol of Fe, therefore, taking into account the practical yield of the reaction:

v (FeCl3) = v (Fe) * 0.9 = 0.25 * 0.9 = 0.225 (mol).

Thus, the mass of the formed iron (III) chloride:

m (FeCl3) = v (FeCl3) * M (FeCl3) = 0.225 * 162.5 = 36.5625 = 36.6 (g).