Question

The automobile fuel called E85 consists of 85% ethanol and 15% gasoline. E85 can be used in so-called flex-fuel vehicles (FFVs), which can use gasoline, ethanol, or a mix as fuels. Assume that gasoline consists of a mixture of octanes (different isomers of C₈H₁₈), that the average heat of combustion of C₈H₁₈(l) is 5400 kJ/mol, and that gasoline has an average density of 0.70 g/mL. The density of ethanol is 0.79 g/mL.By using the information given, calculate the energy produced by combustion of 1.5 L of gasoline.Express your answer to two significant figures and include the appropriate units.

Answer 1

Answer:

49,736.84 kJ

Explanation:

1 L of gasoline has 0.70 kg

1,5 L of gasoline has x kg

1 L - 0.70 kg

1.5 - x

x = 0.7 *1.5 = 1,05 kg

1 mol of gasoline has 114 g

y mol of gasoline has 1050 g

1 mol - 114 g

y - 1050 g

y = $\frac{1050}{114}$ = 9.21 mol

1 mol of gasoline has a combustion heat of 5400 kJ

9.21 mol of gasoline has a combustion heat of z

z = 5400 * 9.21 = 49,736.84 kJ