What amount of hydrogen is formed during the decomposition of 20 g of ethane?

1) Let’s make the equation: C2H6 = 2C + 3H2;
Thermal cracking of ethane results in the formation of carbon and hydrogen gas.
2) Determine the number of moles of ethane, if the mass is known, m (C2H6) = 20g,
M (C2H6) = 30g / mol;
Y (C2H6) = m (C2H6) / M (C2H6); Y (C2H6) = 20/30 = 0.67 mol.
3) Let’s make the proportion:
0.67 mol (C2H6) – X mol (H2)
-1 mol -3 mol
Hence, X mol (H2) = 0.67 * 3/1 = 2.01 mol
4) Let’s calculate the volume of hydrogen. Considering Avogadro’s law.
V (H2) = 2.01 * 22.4 = 45.02L
Answer: When ethane decomposes, 45.02 liters of hydrogen are released.