Three common hydrocarbons that contain four carbons are listed here, along with their standard enthalpies of formation:
Hydrocarbon Formula Heat of formation (kj/mol)
1,3-Butadiene C4H6(g) 111.9
1-Butene C4H8(g) 1.2
n-Butane C4H10(g) -124.7
A) For each of these substances, calculate the molar enthalpy of combustion to CO2(g) and H20(l)
B) Calculate the fuel value in kJ/g for each of these compounds.
C) For each hydrocarbon, determine the percentage of hydrogen by mass.
D) By comparing your answers for parts (b) and (c), propose a relationship between hydrogen content and fuel value in hydrocarbons.