Determine how much oxygen will be spent on the complete combustion of 17.92 liters of ethane?

Decision:
1. Let’s compose the reaction equation:
2С2Н6 + 7О2 = 4СО2 + 6Н2О – combustion reaction, carbon dioxide is released;
2. Let’s write down the values ​​of the molar masses of substances:
M (C2H6) = 12 * 2 = 1 * 6 = 30 g / mol;
M (O2) = 16 * 2 = 32 g / mol;
3. Determine the number of moles of ethane, if its volume is known:
1 mol of C2H6 gas – 22.4 liters. (with n. y);
X mol – 17.92 liters from here, x mol (C2H6) = 1 * 17.92 / 22.4 = 0.8 mol;
4. Let’s calculate the amount of O2 mol;
0.8 mol (C2H6) – X mol (O2);
-2 mol – 7 mol from here, X mol (O2) = 0.8 * 7/2 = 2.8 mol;
5. Determine the volume of O2 by the formula:
V (O2) = 2.8 * 22.4 = 62.72 liters.
Answer: for the combustion reaction, oxygen with a volume of 62.72 liters is required.