By heating aluminum in a stream of chlorine, 26.7 g of aluminum chloride were obtained. How many grams of chlorine has reacted?

Let’s compose the reaction equation:
2Al + 3Cl2 = 2AlCl – the reaction of the compound, aluminum chloride is released;
Let’s calculate the molar masses of chlorine and aluminum chloride:
M (Cl2) = 35.5 * 2 = 71 g / mol; M (AlCl3) = 26.9 + 35.5 * 3 = 133.4 g / mol;
Let us determine the number of moles of AlCl3, if the mass is known:
Y (AlCl3) = m (AlCl3) / M (AlCl3);
Y (AlCl3) = 26.7 / 133.4 = 0.2 mol;
Based on the data on the reaction equation, we will compose the proportion:
X mol (Cl2) – 0.2 mol (Cl2);
-3 mol – 2 mol from here,
X mol (Cl2) = 3 * 0.2 / 2 = 0.3 mol;
Let’s calculate the mass of Cl2 by the formula: m (Cl2) = Y (Cl2) * M (Cl2); m (Cl2) = 0.3 * 71 = 21.3 g.
Answer: chlorine reacted with a mass of 21.3 g.