Question

Assuming that a tank of gasoline contains 80 liters and that its density is 0.77 kg/liter, determine how many kg of co2 are produced for each tank of gasoline burned.

Answer 1

Answer: -

If a tank of gasoline contains 80 liters and that its density is 0.77 kg/liter, 0.26 kg of CO₂ are produced for each tank of gasoline burned.

Explanation: -

Density of the gasoline = 0.77 kg / liter

Volume of the tank containing the gasoline = 80 liter.

Mass of gasoline produced from each tank

= Volume of the tank containing the gasoline x Density of the gasoline

= $\frac{0.77 kg}{1 liter}$ x 80 liter

= 61.6 kg

Chemical formula of gasoline = C₈H₁₈

Molar mass of gasoline C₈H₁₈ = 12 x 8 + 1 x 18 = 114 g/ mol

Number of moles of C₈H₁₈ = $\frac{61.6 g}{114 g}$ x 1 mol

= 0.54 mol of C₈H₁₈

The chemical equation for the burning of gasoline is

2 C₈H₁₈ + 25 O₂ → 16 CO₂ + 18 H₂O

From the balanced equation we see

2 mol of C₈H₁₈ gives 16 mol of CO₂

0.54 mol of C₈H₁₈ gives $\frac{16 mol CO2 x 0.54 mol C8H18}{2 mol C8H18}$ mol of CO₂

= 4.32 mol of CO₂

Molar mass of CO₂ = 12 x 1 + 16 x 3 =60 g / mol

Mass of CO₂ = Molar mass of CO₂ x Number of moles of CO₂

=$\frac{60g x 4.32 mol}{1 mol}$

= 259.2 g

= $\frac{259.2}{1000}$

= 0.259 Kg

= 0.26 kg rounded off to 2 significant figures.

Thus if a tank of gasoline contains 80 liters and that its density is 0.77 kg/liter, 0.26 kg of CO₂ are produced for each tank of gasoline burned.