Question

Is the formation of CO2(g) from its elements endothermic or exothermic?

Answer 1

Answer: Exothermic because the ΔH is negative.

Explanation:

The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements, with all substances in their standard states.

$C(s)+O_2(g)\rightarrow CO_2(g)$

Exothermic reactions are those reactions in which heat is released and $\Delta H$ is negative.Endothermic reactions are those reactions in which heat is absorbed and $\Delta H$ is positive.

The reaction is exothermic as the heat is released during the formation of $CO_2$ as heat of formation of $CO_2$ is negative.