OnlineCBT
Chemistry · THERMODYNAMICS
हिन्दीAt \( 300\text{ K} \), for the reaction \( \text{PCl}_5(g) \rightarrow \text{PCl}_3(g) + \text{Cl}_2(g) \), the value of \( \Delta H \) is \( +124.7\text{ kJ} \). What is the value of \( \Delta U \) for this reaction at the same temperature? (Take \( R = 8.314\text{ J}\cdot\text{K}^{-1}\cdot\text{mol}^{-1} \))
Correct answer · Option 1
\( +122.2\text{ kJ} \)
Explanation
\( \Delta n_g = (1 + 1) - 1 = 1 \). \( \Delta U = \Delta H - \Delta n_g RT = 124.7\text{ kJ} - (1 \times 8.314 \times 300 \times 10^{-3}\text{ kJ}) = 124.7 - 2.494 = 122.2\text{ kJ} \).
