Determine the heat of combustion of acetylene (C2H2).

Answer 1

C2H2 +5/2 O2 ==> 2CO2 + H2O
I would look up the deltaHf for CO2 and for H2O as well as C2H2. Then
delta Hrxn = (n*DHfCO2)+(n*DHfH2O) - (n*DHfC2H2)