Question

What mass of natural gas (CH4) must you burn to emit 275 kJ of heat?
CH4(g)+2O2(g)→CO2(g)+2H2O(g)ΔH∘rxn=−802.3kJ

m =

Pentane (C5H12) is a component of gasoline that burns according to the following balanced equation:
C5H12(l)+8O2(g)→5CO2(g)+6H2O(g)

Part A

Calculate ΔH∘rxn for this reaction using standard enthalpies of formation. (The standard enthalpy of formation of liquid pentane is -146.8 kJ/mol.)

Express your answer using five significant figures.

ΔH∘rxn =

kJ

Answer 1