The mass of benzene obtained from acetylene released from 290.4 g of calcium carbide

The mass of benzene obtained from acetylene released from 290.4 g of calcium carbide (mass fraction of impurities is 9.1 percent) is equal.

Acetylene is synthesized by the interaction of calcium carbide with water.
CaC2 + 2H2O = Ca (OH) 2 + C2H2 ↑;
Let’s calculate the molar amount of calcium carbide.
For this purpose, let us sum up the molar weights of the elements that make up this molecule.
M CaC2 = 40 + 12 x 2 = 64 grams / mol;
N CaC2 = 290.4 x 0.909 / 64 = 4.1246 mol;
Theoretically, the same molar amount of acetylene will be obtained.
From this amount of acetylene, 3 times less benzene can be synthesized.
Let’s calculate its weight:
M C6H6 = 12 x 6 + 6 = 78 grams / mol;
m C6H6 = 4.1246 / 3 x 78 = 107.24 grams.