Iron weighing 2.8 grams reacted with chlorine. The resulting ferric chloride was dissolved in 200 grams of water.

| March 5, 2021 | education

Iron weighing 2.8 grams reacted with chlorine. The resulting ferric chloride was dissolved in 200 grams of water. Calculate the mass fraction of salt in the resulting solution.

Let’s write the reaction equation:

2Fe + 3Cl2 = 2FeCl3

Let’s find the amount of iron substance:

v (Fe) = m (Fe) / M (Fe) = 2.8 / 56 = 0.05 (mol).

According to the reaction equation, 2 mol of FeCl3 is formed from 2 mol of Fe, therefore:

v (FeCl3) = v (Fe) = 0.05 (mol).

Let’s find the mass of the formed iron (III) chloride:

m (FeCl3) = v (FeCl3) * M (FeCl3) = 0.05 * 162.5 = 8.125 (g).

Find the mass of the prepared solution of iron (III) chloride:

mr.-pa (FeCl3) = m (FeCl3) + m (H2O) = 8.125 + 200 = 208.125 (g).

Thus, the mass fraction of iron (III) chloride in solution:

w (FeCl3) = (m (FeCl3) / mp.-pa (FeCl3)) * 100 = (8.125 / 208.125) * 100 = 3.9 (%).

Answer: 3.9%.



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