Sodium Sulfate

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What is Sodium Sulfate?

Sodium sulfate is defined as the sodium salt of sulfuric acid. The sodium sulphate chemical formula is Na2SO4.

Anhydrous sulfate can be described as a white crystalline solid, which is also called mineral thenardite, whereas, the decahydrate Na2SO4.10H2O has been called either mirabilis or Glauber's salt.

When Na2SO4.7H2O is cooled, it is transformed to mirabilite, which is the natural mineral form of decahydrate. About two-thirds of the sodium sulfate's world's production is obtained from mirabilite. It is also formed from the by-products of chemical processes like hydrochloric acid production.

Discovery of Sodium Sulphate

Johann Rudolf Glauber discovered the sodium sulfate in 1625 from Austrian spring water there the hydrate form is called Glauber's salt. Because of its medicinal properties, he named it as sal mirabilis (which is otherwise called miraculous salt).

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Sodium Sulfate Structure

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Until the 1900s, the crystals present here were used as a general-purpose laxative, by reaction either with potash or potassium carbonate, where, in the 18th century, Glauber's salt was used as a raw material for the industrial production of soda ash. In the 19thcentury, the demand for soda ash increased, so the large-scale Leblanc process which produced the synthetic sodium sulfate has become the principal method in the production of soda ash.

At dietary levels, the excretion is primarily in the urine. Sulfates are found in the entire body cells, with the highest concentrations in bone, connective tissue, and cartilage. Sulfates also play a major role in many important metabolic pathways, including those involved in the detoxification processes.

There exist two types of sodium sulfate natural and by-product, which is also called synthetic.

  • Natural sodium sulfate can be produced from naturally occurring crystalline deposits and brines, which are found in Texas and California.

  • It is also found as a constituent of saline lakes, like the Great Salt Lake of Utah. And, the synthetic sodium sulfate is recovered as a by-product of different manufacturing processes.

  • Both sodium sulfate types have many useful and important applications in different consumer products.

  • In a survey of the top 50 basic organic chemicals and inorganic chemicals performed in the United States, sodium sulfate has ranked 47th regarding the quantity produced.


  • Sodium is the 6th most abundant element in the crust of Earth. Geologically, the sodium sulfate-bearing mineral deposits are young, majorly of post-glacial age.

  • It is also widespread in occurrence, and it is a common component of seawater and several alkalis or saline lakes.

  • Economic reserves of natural sodium sulfate are estimated up to 3.3 billion tons worldwide.

  • With world production of this natural sodium sulfate averaging up to 2.6 million tons per year, the supplies are sufficient to meet anticipated demand for many centuries.

  • The synthetic sodium sulfate quantity is dependent on the longevity of the manufacturing firms which are recovering by the sulfate product.

  • Lakes or surface depressions that contain no outlets and are fed by spring waters, which are flowing over volcanic rocks containing sulphide minerals often yield soluble sulphide salts, oxidized by contact with the air for sulfate production.

Properties of Sodium Sulphate

Let us look at some of the properties of Sodium Sulphate tabulated below:

Molecular Weight

322.20gm /mole (decahydrate), 142.04gm/mole (anhydrous)

Molecular Formula





White crystalline solid



Boiling Point

1429℃ (anhydrous)

Melting Point

32.4℃ (decahydrate), 884℃ (anhydrous)

Refractive Index

1.394 (decahydrate), 1.468 (anhydrous)


1.464gm/ml (decahydrate), 2.664gm/ml (anhydrous)


Soluble in glycerol, 

hydrogen iodide, and water; insoluble in ethanol

Sodium Sulphate Uses

  • Sodium sulfate can be used to dry organic liquids.

  • It is used as a filler in-home laundry detergent, in powder form.

  • It can be used as a fining agent which helps to remove small air bubbles from the molten glass.

  • Glauber's salt, which is a decahydrate, was used as a laxative to remove certain drugs like acetaminophen from the body.

  • It is also used for defrosting windows, in carpet fresheners, as an additive to cattle feed starch manufacture.

  • And, it is used in the Kraft process of paper pulping and in detergents manufacturing.


Small-Scale Applications

In the laboratory, anhydrous sodium sulfate can be used widely as an inert drying agent, in the removal of water traces from the organic solutions. It is considered as more efficient, but slower-acting, compared to the same agent, magnesium sulfate. Only, it is effective below 30°C, nearly, but it is used with different materials because it is chemically fairly inert. Sodium sulfate is also added to the solution until the crystals will no longer clump together, but a few of the crystals flow freely once the sample becomes dry.

Glauber's salt, which is the decahydrate, can be used as a laxative. It is also more effective for the removal of specific drugs such as paracetamol (which is also called acetaminophen) from the body, for example, after excess intake or overdose.

FAQ (Frequently Asked Questions)

1. Explain What Happens When the Sodium Sulphate Compound is Reacted With Barium Chloride?

Answer: Sodium sulphate compound reacts with the barium chloride in a double displacement reaction to produce sodium chloride and barium sulphate. The chemical equation for the same can be given as follows:

BaCl2 + Na2SO4 → BaSO4 + 2NaCl

The above-given reaction takes place due to sodium sulphate is an electrostatically bonded ionic sulphate.

2. Explain the Preparation of Sodium Sulphate?

Answer: Sodium sulphate is prepared through the Mannheim process, which can be given by the following reaction:

H2SO4 + 2NaCl → Na2SO4 + 2HCl

It can also be prepared with the Hargreaves process, which is represented below:

4NaCl + 2H2O + 2SO2 + O2 → 2Na2SO4 + 4HCl

3. Mention About the Solubility of Sodium Sulphate in the Water?

Answer: At a temperature of 0℃, the solubility of anhydrous sodium sulphate compound in water can be given as 47.6 gm/litre. Whereas, when heated to 20℃, its solubility increases sharply to 139 gm/litre. Ultimately, at a temperature of 100℃, the solubility of sodium sulphate compound in water corresponds to 427 gms/litre.

4. Explain Sodium Sulphate Safety?

Answer: Although sodium sulfate is regarded as non-toxic, generally, the compound should be handled with care. The dust can cause eye irritation or temporary asthma; this risk can be prevented by using a paper mask and eye protection. Transport is not limited, and no Safety Phrase or Risk Phrase applies.