Enthalpy of Formation Practice Test

Use the standard enthalpies of formation, $\Delta H_f^\circ$, to calculate $\Delta H_{\text{rxn}}^\circ$ for the reaction at 298 K:\n\n$\text{H}_2(g) + \text{Cl}_2(g) \rightarrow 2\text{HCl}(g)$\n\nFormation data (kJ/mol): $\Delta H_f^\circ\text{H}_2(g) = 0$, $\Delta H_f^\circ\text{Cl}_2(g) = 0$, $\Delta H_f^\circ\text{HCl}(g) = -92$.

Use the standard enthalpies of formation, $\Delta H_f^\circ$, given below to calculate $\Delta H_{\text{rxn}}^\circ$ for the reaction at 298 K:

$\text{CH}_4(g) + 2\text{O}_2(g) \rightarrow \text{CO}_2(g) + 2\text{H}_2\text{O}(l)$

Formation data (kJ/mol): $\Delta H_f^\circ\text{CH}_4(g) = -75$, $\Delta H_f^\circ\text{O}_2(g) = 0$, $\Delta H_f^\circ\text{CO}_2(g) = -394$, $\Delta H_f^\circ\text{H}_2\text{O}(l) = -286$.