The enthalpy of combustion of gasoline (C₈H₁₈)is 5471 kJ mol^-1.How much heat will be produced by burning 1 gallon of gasoline at 25^°C? (Density of gasoline = 0.703 g/mL;1gallon = 3.78 L)

Question

Quizplus · Accepted Answer

First, we need to calculate the amount of gasoline in moles present in 1 gallon:

1 gallon = 3.78 L

Density of gasoline = 0.703 g/mL

Mass of gasoline in 1 gallon = 3.78 L x 0.703 g/mL = 2.65934 g

Molar mass of gasoline = 114.23 g/mol

Number of moles of gasoline in 2.65934 g = 2.65934 g / 114.23 g/mol = 0.02326 mol

Now, we can use the enthalpy of combustion to calculate the heat produced:

Enthalpy of combustion of gasoline = 5471 kJ/mol

Heat produced by burning 0.02326 mol of gasoline = 5471 kJ/mol x 0.02326 mol = 127.17746 kJ

Therefore, the heat produced by burning 1 gallon of gasoline at 25°C is approximately 1.3 x 10^5 kJ, which is answer choice A.

The Enthalpy of Combustion of Gasoline (C8H18)is 5471 KJ Mol-1

The Enthalpy of Combustion of Gasoline (C₈H₁₈)is 5471 KJ Mol^-1