How much acetylene is needed to produce 78 grams of benzene?

Let’s carry out the solution in the following sequence:
1) Let us write the equation for obtaining benzene from acetylene:
3C2H2 = C6H6 – the trimerization reaction occurs when heated on a carbon catalyst, benzene is formed;
2) Determine the amount of benzene if the mass is known: m (C6H6) = 78g;
Y (C6H6) = m (C6H6) / M (C6H6); Y (C6H6) = 78/78 = 1 mol;
3) We make the proportion:
X mol (C2H2) – 1 mol (C6H6)
3 mol – 1 mol from here, X mol (C2H2) = 3 * 1/1 = 3 mol.
4) Calculate the volume of acetylene:
V (C2H2) = 3 * 22.4 = 67.2 L;
Answer: for the reaction of obtaining benzene, a volume of 67.2 liters of acetylene is required.