For the phase transformation S(rhombic) ~ S(monoclinic), Δf H∘ (S, monoclinic) =0.33 kJ mol−1,S0 (S, monoclinic) =32.6 JK−1 mol−1 and S∘ ( S, rhombic)=31.8 JK−1 mol−1.The temperature at which the above transformation is in equilibrium is

$Δ_{r} H^{\circ} = {Δe}^{\circ}$ (S monoclinic) $- Δ_{f} H^{\circ}$ (S rhombic) $= 0.33 kJ {mol}^{- 1} - 0 = 0.33 kJ {mol}^{- 1}$

$Δ_{r} S^{\circ} = S^{\circ}$ (S, monoclinic) $- S^{\circ}$ (S, rhombic) $= (32.6 - 31.8) {JK}^{- 1} {mol}^{- 1} = 0.8 {JK}^{- 1} {mol}^{- 1}$

$T = \frac{Δ_{r} H^{\circ}}{Δ_{r} S^{\circ}} = \frac{0.33 \times 10^{3} J {mol}^{- 1}}{0.8 {JK}^{- 1} {mol}^{- 1}} = 412.5 K$

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