Chemistry 9701 · AS & A Level · Chemical energetics

Chemical energetics — practice question

$\Delta H_1^\circ$ represents the standard enthalpy of formation of methane. $\Delta H_2^\circ$ represents the standard enthalpy of combustion of carbon. $\Delta H_3^\circ$ represents the standard enthalpy of combustion of hydrogen. $\text{CH}_4(g) + 2\text{O}_2(g) \xrightarrow{\Delta H_c^\circ} \text{CO}_2(g) + 2\text{H}_2\text{O}(l)$ Which expression is equal to $\Delta H_c^\circ$?

  • A$\Delta H_1^\circ - \Delta H_2^\circ + \Delta H_3^\circ$
  • B$\Delta H_1^\circ - 2\Delta H_3^\circ - \Delta H_2^\circ$
  • C$\Delta H_2^\circ - \Delta H_3^\circ + \Delta H_1^\circ$
  • D$\Delta H_2^\circ + 2\Delta H_3^\circ - \Delta H_1^\circ$

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