How many liters of water can be formed if 1.26 liters of ethylene (C2H4) are consumed in this reaction

The reaction of ethylene (ethene) is:

C2H4 (g) + 3O2 (g) → 2CO2 (g) + 2H2O (g)

The molar ratio of C2H4 to water is 1molC2H4 : 2 mol H2O

The volumes of ideal gases at constant temperature and pressure are proportional to the number of mols.

Then, you can state that the volumetric ratio of the two gases is the same that above molar ratio:

1 Liter C2H4 : 2 Liter H2O

Given that you have 1.26 Liter C2H4, the volume of water is:

1.26 Liter C2H4 * [2 Liter H2O / 1 Liter C2H4] = 2.52 Liter H2O

Answer: 2.52 Liter of water.