Sulfur is a nonpolar molecule and dissolve in nonpolar solution. But, its solubility varies significantly to different nonpolar solutions. Like, it has a very high solubility to carbon-di-sulfide (34 wt% in CS2) and very low solubility in n-hexane (0.4 wt%). Does anyone know, the reason behind this? Moreover, I also need to know whether sulfur is soluble to n-pentane or not. If yes, what is the solubility limit in n-pentane. Thanks for your response.
The solubility of crystalline elemental sulfur consisting of S8 cyclic molecules, which cohesion is ensured by London dispersion forces, is favoured by solvent-solute intermolecular forces of the same type and comparable strength. Such dispersion forces, which require polarizable solvent molecules, are higher for aromatic or aliphatic unsaturated hydrocarbons, and also for carbon disulfide, owing to its hetero double bonds. That is not the case of the aliphatic saturated hydrocarbonds n-hexane and n-pentane; hence poor solvents for the orthorhombic polymorph of sulfur.
Thank you very much Carlos for your logical and descriptive answer.
I am not aware of any (public) data for nC5 but data are available for hexane and heptane, check the sulphur data book.
Thanks Antonin, could you please provide me the link of that book?
Sorry it is a quite an old book and I have no electronic copy.
Please find enclosed a picture of the page in question.
Thank you very much Antonin. Could you please tell me, is there any commercial organic solvent available which is nonpolar (hydrophobic, just like sulfur) and has a very low solubility of sulfur? Thanks.
Sorry I don't know of any commercial solvent, S8 solubility in alcohol is lower than most non polar organic solvent. Hexane has the lowest S8 solubility of the non-polar solvent for which I have data.
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