Chemistry - Thermochemistry Question with Solution | TestHub

Given,$\text{2C}\text{+}{\text{3H}}_{\text{2}}\to {\text{C}}_{\text{2}}{\text{H}}_{\text{6}}\text{; }\text{ΔH}\text{=}-\text{21}\text{.1}$
$\text{C}\text{+}{\text{O}}_{\text{2}}\to {\text{CO}}_{\text{2}}; \text{ΔH}=-94.1$
${\text{H}}_{\text{2}}+\frac{1}{2}{\text{O}}_{\text{2}}\to {\text{H}}_{\text{2}}\text{O}; \text{ΔH}=-68.3$
Eqs.$2\times \text{(ii)}+3\times \text{(iii)}-\text{(i)}$
${\mathrm{C}}_2{\mathrm{H}}_6+\frac{7}{2}{\mathrm{O}}_2\to 2\mathrm{C}{\mathrm{O}}_2+3{\mathrm{H}}_2\mathrm{O}$
$\text{Δx}=2\left(-94.1\right)+3\left(-68.3\right)-\left(-21.1\right)$
$=-372 \text{kcal/mol}$