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Why does sulphur exist in two forms in solid state, monoclinic and rhombic? Why in one favoured over another at a certain temperature and pressure?

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Why is rhombic sulphur more stable at lower temperature and monoclinicdoes sulphur at higher temperatureexist in two forms in solid state, when the molecular formula is $S_8$ for bothmonoclinic and rhombic?

Both Rhombic and Monoclinic sulphur consist of $S_8$ molecules packed together. Yet the former is more stable below $96^{\circ}C$$114^{\circ}C$ at 1 atm and spontaneously converts to monoclinic sulphur above that temperature. Does this have something to do with the crystal structure? Gibbs equation tells us that structures with higher entropy are preferred at a higher temperature.

Even at the same temperature we can see that rhombic form is more common at higher pressures. Is pressure decreasing the entropy and favouring one form over another?

enter image description here

Does that mean a monoclinic structure has higher entropy and lower enthalpy, if that's true why is entropy higher? Or is my hypothesis wrong and it's based on something completely different.

Why is rhombic sulphur more stable at lower temperature and monoclinic sulphur at higher temperature, when the molecular formula is $S_8$ for both?

Both Rhombic and Monoclinic sulphur consist of $S_8$ molecules packed together. Yet the former is more stable below $96^{\circ}C$ and spontaneously converts to monoclinic sulphur above that temperature. Does this have something to do with the crystal structure? Gibbs equation tells us that structures with higher entropy are preferred at a higher temperature.

enter image description here

Does that mean a monoclinic structure has higher entropy and lower enthalpy, if that's true why is entropy higher? Or is my hypothesis wrong and it's based on something completely different.

Why does sulphur exist in two forms in solid state, monoclinic and rhombic?

Both Rhombic and Monoclinic sulphur consist of $S_8$ molecules packed together. Yet the former is more stable below $114^{\circ}C$ at 1 atm and spontaneously converts to monoclinic sulphur above that temperature. Does this have something to do with the crystal structure? Gibbs equation tells us that structures with higher entropy are preferred at a higher temperature.

Even at the same temperature we can see that rhombic form is more common at higher pressures. Is pressure decreasing the entropy and favouring one form over another?

enter image description here

Does that mean a monoclinic structure has higher entropy and lower enthalpy, if that's true why is entropy higher? Or is my hypothesis wrong and it's based on something completely different.

added 91 characters in body
Source Link
Tatai
Tatai
  • 337
  • 2
  • 18

Both Rhombic and Monoclinic sulphur consist of $S_8$ molecules packed together. Yet the former is more stable below $96^{\circ}C$ and spontaneously converts to monoclinic sulphur above that temperature. Does this have something to do with the crystal structure? Gibbs equation tells us that structures with higher entropy are preferred at a higher temperature.

enter image description here

Does that mean a monoclinic structure has higher entropy and lower enthalpy, if that's true why is entropy higher? Or is my hypothesis wrong and it's based on something completely different.

Both Rhombic and Monoclinic sulphur consist of $S_8$ molecules packed together. Yet the former is more stable below $96^{\circ}C$ and spontaneously converts to monoclinic sulphur above that temperature. Does this have something to do with the crystal structure? Gibbs equation tells us that structures with higher entropy are preferred at a higher temperature.

Does that mean a monoclinic structure has higher entropy and lower enthalpy, if that's true why is entropy higher? Or is my hypothesis wrong and it's based on something completely different.

Both Rhombic and Monoclinic sulphur consist of $S_8$ molecules packed together. Yet the former is more stable below $96^{\circ}C$ and spontaneously converts to monoclinic sulphur above that temperature. Does this have something to do with the crystal structure? Gibbs equation tells us that structures with higher entropy are preferred at a higher temperature.

enter image description here

Does that mean a monoclinic structure has higher entropy and lower enthalpy, if that's true why is entropy higher? Or is my hypothesis wrong and it's based on something completely different.

Source Link
Tatai
Tatai
  • 337
  • 2
  • 18