Anhydrous sodium sulfate is an important compound of sodium. It is a white crystalline solid. In its natural form, it occurs in arid regions as a mineral. It is also a common inert drying agent for organic solutions.
The chemical formula of sodium sulfate is Na2SO4*10H2O. It is prepared by the reaction of sulfuric acid with sodium hydroxide. As a result, it is neutral in an aqueous solution. However, the equilibrium between the two is strongly dependent on the concentration of other acid salts. For example, at a pH value of 10, sodium sulfate has a solubility of 47.6 grams per litre in water.
In the US, in 1995, sodium sulfate was sold for about $70 a tonne. It is used in many applications, including as a “fining agent” in paper pulp, glass and detergent manufacture. Also, it is useful for chemical analysis reagents.
Sodium sulfate is a naturally occurring mineral. The mineral consists of an orthorhombic crystal system. Originally, it was used as a laxative.
In its granular form, Glauber’s salt is a stripy-white crystal with a double cone. It is easily hydrated in humid air.
Sodium sulfate has no smell and is not combustible. Nevertheless, it should be stored dry indoors. After handling it, rinse it thoroughly with water.
Anhydrous sodium sulfate can be used as a ‘fining agent’ to remove small air bubbles from molten glass. This process is commonly called the Kraft process. Currently, this process is being replaced by other processes.