What is Specific Surface?
The specific surface (or specific surface are) of a solid substance is the surface area per unit mass. The SI units are m2/kg.
Specific surface is important for the design of chemical processes that involve surface reactions. For example, the material used to provide a catalyst bed needs to have a large surface area.
Specific surface is difficult to measure directly, but can often be calculated from knowledge of the surface structure and making reasonable approximations. Generally the smoother the surface, the lower will be the specific surface.