The enthalpy of combustion (in kcal/mol) of liquid is — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

Target reaction: $\text{N}_2\text{H}_4\text{(l)} + \text{O}_2\text{(g)} \to \text{N}_2\text{(g)} + 2\text{H}_2\text{O(l)}$. By applying Hess's Law algebraically combining equations (a), (b), (c), and (d) to eliminate $\text{NH}_3$, $\text{N}_2\text{O}$, and $\text{H}_2$, the calculated net enthalpy change equals $-148.84\text{ kcal/mol}$.