Determine the mass of methane required to obtain 8.96 liters of acetylene.

Let’s implement the solution:
1. We compose the equation according to the condition:
X g -? V = 8.96 L;
2CH4 = C2H2 + 3H2 – decomposition of methane, obtained acetylene, hydrogen;
2. Proportions:
1 mol of gas at normal level – 22.4 liters;
X mol (C2H2) – 8.96 L. hence, X mol (C2H2) = 1 * 8.96 / 22.4 = 0.4 mol;
X mol (CH4) – 0.4 mol (C2H2);
-2 mol -1 mol hence, X mol (CH4) = 2 * 0.4 / 1 = 0.8 mol.
3. Find the mass of the original substance:
m (CH4) = Y * M = 0.8 * 16 = 12.8 g.
Answer: to carry out the decomposition process, methane with a mass of 12.8 g is required.