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Chemistry · THERMODYNAMICS
हिन्दीFor the dissociation of one mole of \( \text{NaCl(s)} \) into gaseous ions: \( \text{NaCl(s)} \rightarrow \text{Na}^+(\text{g}) + \text{Cl}^-(\text{g}) \), the lattice enthalpy is \( +788\text{ kJ mol}^{-1} \). The corresponding internal energy change (\( \Delta U \)) is smaller than lattice enthalpy by:
Correct answer · Option 1
\( 2RT \)
Explanation
Since \( \Delta n_g = 2 - 0 = 2 \), \( \Delta H = \Delta U + \Delta n_g RT = \Delta U + 2RT \), so \( \Delta U = \Delta H - 2RT \).
