Benzene was obtained from 6.72 liters of acetylene. Find the mass of benzene. If q the product yield is 75%.

Let’s implement the solution:
1. In accordance with the condition of the problem, we write the equation:
V = 6.72 liters. X g -? W = 75%
3C2H2 = C6H6 – trimerization, benzene was obtained.
2. Calculations of the molar masses of substances:
M (C2H2) = 26 g / mol;
M (C6H6) = 78 g / mol.
3. Determine the amount of the original substance:
1 mol of gas at normal level – 22.4 liters;
X mol (C2H2) – 6.72 L. hence, X mol (C2H2) = 1 * 6.72 / 22.4 = 0.3 mol.
4. Proportion:
0.3 mol (C2H2) – X mol (C6H6);
3 mol 1 mol from here, X mol (C6H6) = 0.3 * 1/3 = 0.1 mol.
5. Find the mass of the product:
m (C6H6) = Y * M = 0.1 * 78 = 7.8 g.
m (practical) = 0.75 * 7.8 = 5.85 g.
Answer: benzene weighing 5.85 g was obtained.