1) Write the chemical equations.
1.1-The chemical equation result.
[tex]A+B\rightarrow C[/tex]
1.2-The chemical equation steps.
[tex]2A+B\rightarrow D\text{ }(\Delta H_1^0)[/tex][tex]C+A\rightarrow D\text{ }(\Delta H_2^0)[/tex]
2) Invert the second step.
[tex]D\rightarrow C+A\text{ }(-\Delta H_2^0)[/tex]
3) Sum up the equation steps.
[tex]\begin{gathered} 2A+B\rightarrow D \\ D\rightarrow C+A \end{gathered}[/tex][tex]A+B\rightarrow C[/tex]
Enthalpy change
[tex]\Delta H^0=\Delta H_1^0-\Delta H_2^0[/tex]
Option C.
.
