Chemistry Question from JEE Main 2025 · 22 January, Shift 2

Consider the following cases of standard enthalpy of reaction ($\Delta H_r^\circ$ in $\text{kJ mol}^{-1}$):

$$\text{C}_2\text{H}_6(g) + \frac{7}{2} \, \text{O}_2(g) \rightarrow 2 \, \text{CO}_2(g) + 3 \, \text{H}_2\text{O}(l) \quad \Delta H_1^\circ = -1550$$ $$\text{C(graphite)} + \text{O}_2(g) \rightarrow \text{CO}_2(g) \quad \Delta H_2^\circ = -393.5$$ $$\text{H}_2(g) + \frac{1}{2} \, \text{O}_2(g) \rightarrow \text{H}_2\text{O}(l) \quad \Delta H_3^\circ = -286$$

The magnitude of $\Delta H_f^\circ$ of $\text{C}_2\text{H}_6(g)$ is _____ $\text{kJ mol}^{-1}$ (Nearest integer).