The mass of methane required to obtain 8.96 liters of acetylene is …

In accordance with the condition of the problem, we write the equation:
2СН4 = С2Н2 + 3Н2 – methane decomposition reaction, cracking, acetylene and hydrogen are formed;
Let’s calculate the molar masses of substances:
M (CH4) = 16 g / mol;
M (C2H2) = 26 g / mol;
Determine the number of moles of acetylene:
Y (C2H2) = 1 * 8.96 / 22.4 = 0.4 mol;
Let’s make the proportion:
X mol (CH4) – 0.4 mol (C2H2);
– 2 mol -1 mol from here, X mol (CH4) = 2 * 0.4 / 1 = 0.8 mol;
Let’s calculate the mass of methane by the formula:
m (CH4) = Y * M = 0.8 * 16 = 12.8 g.
Answer: the reaction requires methane with a mass of 12.8 g.