Enthalpy question

Question

The heats of formation of CH​4(​ g), H​2O​ (g) and CO(g) are -890.4 kJ mol-​ 1​, -241.8 kJ mol-​ 1 and -110.5 kJ mol-​ 1​ respectively. Determine the enthalpy change for the reaction and state whether it is exothermic or endothermic.

Answer 1

Once again, you neglected to include the reaction of interest. We cannot answer this without knowing the reaction. One might assume it to be CH₄ + 2O₂ ==> CO₂ + 2H2O but you must include the reaction so we can be sure.