Question

Of the three varieties of cyclo-octasulphur polymorphs - the alpha, beta and gamma forms, the most stable polymorph near room temperature is __.

Answer 1

Of the three polymorphs, the $\alpha$ -Sulphur or the rhombic Sulphur is the most stable (below ${95.3}^{\circ }C$) and also the most common one. The $\beta$ -Sulphur or monoclinic Sulphur is stable only above ${95.3}^{\circ }C$. At temperatures above ${95.3}^{\circ }C$ $\alpha$-Sulphur turns into $\beta$ -Sulphur. The $\gamma$ -Sulphur is the densest of the three $S_8$ polymorphs. It can be prepared by slowly cooling molten Sulphur that has been heated above ${150}^{\circ }C$