Question

Rhombic Sulphur consists of:
(A) ${S_5}$ chains
(B) ${S_2}$ molecules
(C) ${S_4}$ rings
(D) ${S_8}$ rings

Answer 1

Sulphur forms numerous allotropes but let us study the two most important allotropes of Sulphur:
Yellow rhombic sulphur$\left( {\alpha - {\text{sulphur}}} \right)$and the monoclinic$\left( {\beta - {\text{sulphur}}} \right)$. The most interesting feature is their thermal stability, the allotropes of Sulphur are interconvertible, i.e. rhombic Sulphur when heated above $369K$gives monoclinic Sulphur.

Complete step by step answer:
(A) Stable form of Sulphur that exists at room temperature or can say below $369K$ is rhombohedral which exists as ${S_8}$ rings.
(B) ${S_2}$ molecule does not exist due to low bond enthalpy of S-S bond.
(C) ${S_4}$ rings has more angle strain so unstable at room temperature
(D) Sulphur does not show catenation because S-S bond enthalpy is less than Sulphur bond with others. It is insoluble in water. But readily soluble in $C{S_2}$ .

So, the correct answer is D.

Additional information:
It is insoluble in water but dissolves to some extent in benzene , alcohol and ether . It is readily soluble in $C{S_2}$ .
It has little thermal and electrical conductivity .
It consists of eight Sulphur atoms arranged in an octahedral shape. All other allotropes of Sulphur gradually change into rhombic Sulphur.

Rhombic Sulphur is the most stable variety of Sulphur. It melts at ${112.8^\circ }C$.

Note:
When slowly heated to ${96^\circ }C$, it changes into monoclinic or $\beta - {\text{sulphur}}$ . However, when cooled below ${96^\circ }C$ , it returns back to rhombic form.
Rhombic Sulphur is prepared by dissolving powdered Sulphur in carbon disulphide at room temperature.