Sulfur

Sulfur comes in many forms. The form whose properties will be discussed here is the molecular solid solid S 8.

This solid consists of numerous S 8 molecules joined together by weak intermolecular forces (van der Waals forces). The molecule itself is made up of eight sulfur atoms covalently bonded together, and looks like this:



=What are the properties of this solid?=

Melting/boiling points:
Sulfur melts at 115.21 °C, and boils at 444.6 °C. The reason it has these relatively low melting and boiling points is that it is a discrete molecular solid, ie it is made of molecules joined together by weak intermolecular forces. The fact that these forces are weak mean little (heat) energy is needed to break them, resulting in the low melting/boiling points. When comparing sulfur's boiling point to that of water, we notice that sulfur's is significantly higher, even though they are both made of molecules. This can be explained by the fact that the heavier the molecules the higher the boiling point, because there will be more intermolecular attraction between them. The sulphur molecule's mass is greater than that of water.

Electrical Conductivity:
Sulfur is made up of sulfur **molecules** in which sulfur atoms are covalently bonded to each other. It **does not contain mobile charged particles** (no free electrrons or mobile ions). Therefore sulfur cannot conduct in the solid or liquid state.

Solubility:
Sulfur S 8 is a non polar molecule. Because of this it will not dissolve in water as the force of attraction between the polar water molecules and non polar sulfur molecules are extremely weak. These forces cannot overcome the intermolecular forces holding the sulfur together. This is also true for other polar substances. Remember that //like dissolves like// so S 8 would dissolve in non polar substances.

Malleability and Ductility:
Sulfur is brittle and if beaten flat sulfur would shatter. It has low malleability and is not very hard nor ductile.