Question

A major 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 carbon dioxide is produced by the reaction of 9.88 g of oxygen gas?

Round your answer to 3 significant digits.

Answer 1

Answers:

8.70 g

Step-by-step explanation:

We know we will need a balanced equation with masses and molar masses, so let’s gather all the information in one place.  

M_r:                   32.00      44.01

           2C₈H₁₈ + 25O₂ ⟶ 16CO₂ + 18H₂O

m/g:                    9.88

(a) Calculate the moles of O₂

n = 9.88 g O₂ ×1 mol O₂ /32.00 g O₂

n = 0.3088 mol O₂

(b) Calculate the moles of CO₂

The molar ratio is (16 mol CO₂/25 mol O₂)

n = 0.3088 mol O₂ × (16 mol CO₂/25 mol O₂)

n = 0.1976 mol CO₂

(c) Calculate the mass of CO₂

Mass of CO₂ = 0.1976 mol CO₂ × (44.01 g CO₂/1 mol CO₂)

Mass of CO₂ = 8.70 g CO₂