Aluminum powder with a mass of 29.7 was mixed with a sulfur powder with a mass of 67.2

Aluminum powder with a mass of 29.7 was mixed with a sulfur powder with a mass of 67.2 and heated without access to air. Find the mass of salt formed.

Let’s execute the solution:
1. In accordance with the condition of the problem, we compose the equation:
2Al + 3S = Al2S3 – compounds, obtained aluminum sulfide;
2. Let’s make calculations using the formulas:
M (Al) = 26.9 g / mol;
M (S) = 32 g / mol;
M (Al2S3) = 149.8 g / mol.
3. Determine the amount of starting materials:
Y (Al) = m / M = 29.7 / 26.9 = 1.1 mol (deficient substance);
Y (S) = m / M = 67.2 / 32 = 2.1 mol (substance in excess).
Calculations are made for the substance in deficiency.
4. Proportion:
1.1 mol (Al) – X mol (Al2S3);
-2 mol -1 mol hence, X mol (Al2S3) = 1.1 * 1/2 = 0.55 mol.
5. Find the mass of the product:
m (Al2S3) = Y * M = 0.55 * 149.8 = 82.39 g.
Answer: Received aluminum sulfide weighing 82.39 g.