Standard molar enthalpy of formation of is equal to — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

The standard state of carbon is graphite. The standard formation reaction of $CO_2$ is: C(graphite, s) + $O_2$(g) -> $CO_2$(g), which is identical to the combustion reaction of carbon (graphite). Thus, standard molar enthalpy of formation of $CO_2$ is equal to the standard molar enthalpy of combustion of carbon (graphite).