Amajor component of gasoline is octane c8h18 . when octane 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 9.8g of octane

The reaction of octane with oxygen can be illustrated by the following chemical equation:
2C8H18 + 25O2 > 16CO2 + 18H2O

From the periodic table:
molecular mass of carbon = 12 grams
molecular mass of oxygen = 16 grams
molecular mass of hydrogen = 1 gram
therefore,
molar mass of octane = 8(12)+18(1) = 114 grams
molar mass of water = 2(1) + 16 = 18 grams

From the balanced chemical equation, we can notice that:
2 x 114 = 228 grams of octane are required to produce 18 x 18 = 324 grams of water.
Therefore, to know the amount of water produced from 9.8 grams of octane, we will simply do cross multiplication as follows:
amount of water = (9.8 x 324) / 228 = 13.926 grams