Verified Solution • 2025–26 Session moderate QJEEAdv23Ch7c9f: JEE Advanced 2023 Chemistry - Class 11 JEEAdv23Ch7c9f Solution: The value of enthalpy change, H β − H α… The value of enthalpy change, Hβ−Hα (in Jmol−1 ), at 300 K is ________. Step-by-Step Verified Solution As the phase transition temperature is 600 K600 \mathrm{~K}600 K So at 600 KΔGrxn∘=0600 \mathrm{~K} \quad \Delta \mathrm{G}_{\mathrm{rxn}}^{\circ}=0600 KΔGrxn∘=0 So ΔH∘reaction (600) =TΔS∘reaction (600) \Delta \mathrm{H}^{\circ}{ }_{\text {reaction (600) }}=\mathrm{T} \Delta \mathrm{S}^{\circ}{ }_{\text {reaction (600) }}ΔH∘reaction (600) =TΔS∘reaction (600) ΔH∘(600)=600×1=600Joule/mole\Delta \mathrm{H}^{\circ}{ }_{(600)}=600 \times 1=600 \mathrm{Joule} / \mathrm{mole}ΔH∘(600)=600×1=600Joule/mole So ΔH600−ΔH300=ΔCP(T2−T1)\Delta \mathrm{H}_{600}-\Delta \mathrm{H}_{300}=\Delta \mathrm{C}_{\mathrm{P}}\left(\mathrm{T}_2-\mathrm{T}_1\right)ΔH600−ΔH300=ΔCP(T2−T1) ΔH600−ΔH300=1×300\Delta \mathrm{H}_{600}-\Delta \mathrm{H}_{300}=1 \times 300ΔH600−ΔH300=1×300 ΔH300=ΔH600−300=600−300=300\Delta \mathrm{H}_{300}=\Delta \mathrm{H}_{600}-300=600-300=300ΔH300=ΔH600−300=600−300=300 Joule /// mole. Related Learning Resources & Exam Preparation JEE Advanced PYQ Question Bank Browse year-wise authentic previous years' questions with solutions Authentic CBT Mock Tests Simulate official exam environment with live timer and percentile scoring