OnlineCBT
Chemistry · THERMODYNAMICS
हिन्दीGiven the following thermochemical equations: (i) \( \text{C}(\text{graphite}) + \text{O}_2(g) \to \text{CO}_2(g);\; \Delta_r H^\ominus = -393.5\text{ kJ mol}^{-1} \) (ii) \( \text{CO}(g) + \frac{1}{2}\text{O}_2(g) \to \text{CO}_2(g);\; \Delta_r H^\ominus = -283.0\text{ kJ mol}^{-1} \) The enthalpy change for \( \text{C}(\text{graphite}) + \frac{1}{2}\text{O}_2(g) \to \text{CO}(g) \) is:
Correct answer · Option 4
\( -110.5\text{ kJ mol}^{-1} \)
Explanation
Subtracting equation (ii) from equation (i): \( \Delta_r H^\ominus = -393.5 - (-283.0) = -110.5\text{ kJ mol}^{-1} \).
