When octane (C8H18) is burned in air, it chemically reacts with oxygen gas (O2) to produce carbon dioxide (CO2) and water (H2O). What mass of water is produced by the reaction of 1.3g of oxygen gas?

Answer 1

2C₈H₁₈ + 25O₂ ==> 16CO₂ + 18H₂O ... BALANCED EQUATION

Assuming the octane is present in excess, we can find the mass of water produced.

1.3 g O2 x 1 mol O2/32 g = 0.0406 moles O2

0.0406 mol O2 x 18 mol H2O / 25 mol O2 = 0.0293 mol H2O produced

0.0293 mol H2O x 18 g H2O/mol = 0.53 g H2O produced