Question

Calculate the approximate enthalpy change , ΔH∘, for the combustion of methane: CH4+2O2⇌2H2O+CO2 Use the values you calculated in Parts A to D, keeping in mind the stoichiometric coefficients.

Answer 1

Answer:

ΔH° = 676 kJ

Explanation:

The approximate enthalpy change of the combustion of methane can be obtained by subtracting the enthalpies of the reactants from the products. The combustion of methane is shown using the chemical equation below:

C$H_{4}$ + 2$O_{2}$ ⇔ 2$H_{2}O$ + C$O_{2}$

Therefore, the approximate enthalpy change is:

ΔH° = 2*(Δ$H_{H_{2}O }$) + Δ$H_{CO_{2} }$ - Δ$H_{CH_{4} }$ - 2*(Δ$H_{O_{2} }$) = 2(928)+1472-1656-2(498) = 676 kJ

The approximate enthalpy change is 676 kJ.

We used only the magnitude of the enthalpies for the calculation.