Answer to Question #96154 in Chemistry for Chrisam

Question

How many grams of H2O are produced by the complete combustion of 3.0 x 10² g of octane, C8H18 in gasoline?

Answer 1

According to the reaction of octane combustion:

2C₈H₁₈ + 25O₂ = 16CO₂ + 18H₂O

The number of moles of octan must be equal to the number of moles of produced water. As a result:

m_octane / (2 × Mr_octane) = m_water / (18 × Mr_water)

From here:

m_water = m_octane × 18 × Mr_water / (2 × Mr_octane) = 3 × 10² g × 18 × 18 g/mol / (2 × 114 g/mol) = 426 g

Answer: 426 g ow H₂O