Consider the combustion reaction,

2C4H2+5O 2--->4 CO2+2H2O

where C2 H2 Hf = 227.4 kJ/mol), CO2 (Hf = –393.5 kJ/mol), and H2 O (Hf = –241.82 kJ/mol). What is the enthalpy of the reaction?


–2,512.4 kJ

–1,256.2 kJ

1,256.2 kJ

2,512.4 kJ