Chapter 15, Problem 82A

Interpretation Introduction

Interpretation: The thermochemical equation for the combustion of methane needs to be determined.

Concept Introduction: The thermochemical reaction mentions the reactants, the products and the thermodynamic state of the reaction.

Answer to Problem 82A

The thermochemical equation for the combustion of methane is:

  ${\text{CH}}_{\text{4}}{\text{(g)+2O}}_{\text{2}}\text{(g)}\to {\text{CO}}_{\text{2}}{\text{(g)+2H}}_{\text{2}}\text{O(l),Δ}{H}_{\text{comb}}\text{=}-\text{891 kJ/mol}$

Explanation of Solution

The combustion reaction of methane is as follows:

  ${\text{CH}}_{\text{4}}{\text{(g)+2O}}_{\text{2}}\text{(g)}\to {\text{CO}}_{\text{2}}{\text{(g)+2H}}_{\text{2}}\text{O(l)}$

The above chemical equation becomes a thermochemical equation when the enthalpy change is mentioned with the equation.

Thus, the thermochemical equation for the combustion of methane is as follows:

  ${\text{CH}}_{\text{4}}{\text{(g)+2O}}_{\text{2}}\text{(g)}\to {\text{CO}}_{\text{2}}{\text{(g)+2H}}_{\text{2}}\text{O(l),Δ}{H}_{\text{comb}}\text{=}-\text{891 kJ/mol}$