Learn Chemistry: Glossary


A glossary for Learn Chemistry explaining the meaning of chemistry terms used within this site.

Type of Activity

group work, working independently



Age Group

16 to Undergraduate
Term Definition
Sealing film A polymeric film used to temporarily seal aqueous solutions preventing evaporation.
Silica gel Silica gel is a granular, vitreous, porous form of silicon dioxide used for:
1. The stationary phase in chromatographic separations.
2. A desiccant (drying agent) used in desiccators which is often treated with cobalt chloride which will turn from blue to pink as the desiccant becomes exhausted.
Silicone grease

A grease that is used as a thin film on glass joints to prevent them from seizing and to seal them in reduced pressure distillations. It may also be used to seal the lids of desiccators.

Sintered glass A type of glass that is made by heating powdered glass below its melting point so that the particles stick to each other. The result is a material which will allow liquids to pass through it but it will retain solid material. Sintered glass can be used to make filters as well as support the stationary phase in chromatography columns.
Standard (solution) A solution of precisely known concentration used in volumetric analysis.
Standardisation Using volumetric analysis to detrmine the exact concentration of a standard solution.
Stationary phase The solid phase in a chromatographic separation.
Stoichiometry The number of moles involved in a reaction in accordance with the balanced equation.