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What is Glauber’s salt?

The Glauber's salt is the decahydrate sodium sulphate form. It can also be called the mirabilite. The chemical formula for the Glauber’s salt is denoted by Na2SO4.10H2O. This salt is the vitreous mineral with the white or colourless appearance. This forms the evaporite from the brines comprising of the sodium sulphate. You should also note that the compound is known to form naturally along the saline springs and saline playa lakes. The name of the Glauber’s salt was given after the German-Dutch chemist and the alchemist - Johann Rudolf Glauber.

The Structure of the Glauber’s salt

The decahydrate crystals contain the [Na(OH2)6]+ ions having octahedral molecular geometry. The octahedra shares the edges. 8 out of these 10 water molecules are further bound to the sodium, and the remaining two are hydrogen bonds, interstitial and they are bonded to the sulphate. The resulting cations are linked to sulphate anions via hydrogen bonds. The crystalline sodium sulphate decahydrate is uncommon amongst hydrated salts for having the moderate residual entropy of 6.32 J⋅K−1⋅mol−1. This indicates the ability of distributing water rapidly in comparison to most other hydrates.

The Properties of Glauber’s salt

Physical properties: The Glauber’s salt or the sodium sulphate the unusual soluble characteristics in the water. The solubility for this specific compound in the water goes up ten times ranging between 0 degrees celsius to 32.384 degrees celsius, and at that point it reaches 49.7g/100 ml as the maximum level. At this point, the curve of solubility changes into slope and solubility becomes considerably independent of the temperature. 

Chemical properties: Typically, the sodium sulphate is the electrostatically bonded ionic sulphate. The existence of the free sulphate ions in the solution is represented by easy formation of insoluble sulphates when the solutions are treated with Pb2+ Ba2+ salts and the chemical equation is as follows: Na2SO4 + BaCl2 → NaCl + BaSO4. The Glauber’s salt tends to be unreactive towards most of the oxidising or reducing agents. It gets converted to sodium sulphide at higher temperatures with the help of carbothermal reduction. 

The Uses of Glauber’s Salt

Glauber's salt is widely used as the laxative in numerous medications. This compound is also effective in the removal of excessive drugs, such as paracetamol, from the body when it is used in overdose. This compound is also useful for storing low-grade solar heat when it is transforming from the solid phase to the liquid phase. The chemical industry also uses Glauber's salt for producing several important chemicals from a commercial point of view.

Chemical Properties

Typically, sodium sulphate is an electrostatically bonded ionic sulphate. The free sulphate ions’ existence in the solution is represented by the easy formation of the insoluble sulphates when these solutions are treated either with Pb2 + Ba2 + salts, where the chemical equation is listed below.

Na2SO4 + BaCl2 → 2 NaCl + BaSO4

Glauber's salt is unreactive toward most reducing or oxidising agents. It is converted to the sodium sulphide at higher temperatures using the carbothermal reduction (heating with charcoal, and more, at high temperature) as represented with the chemical equation below.

Na2SO4 + 2C → Na2S + 2CO2

This chemical reaction was employed in the process of Leblanc, which is a defunct industrial route to the sodium carbonate.

Glauber's salt reacts with the sulfuric acid to produce acid salt sodium bisulfate, where the chemical equation is represented below.

Na2SO4 + H2SO4 ⇌ 2 NaHSO4

Glauber's salt shows a moderate tendency to form double salts. The only alums that are produced with common trivalent metals are NaCr(SO4)2 and NaAl(SO4)2 (unstable above 39℃), in contrast to ammonium sulphate and potassium sulphate, which form various stable alums. Double salts with a few other alkali metal sulphates are known, including the Na2SO4·3K2SO4 that occurs naturally similar to mineral aphthitalite. The formation of glaserite via sodium sulphate reaction with potassium chloride has been used as a method for the production of potassium sulphate, which is a fertiliser. Another double salt is NaF·Na2SO4.

Production of Glauber's Salt

The world production of Glauber's salt or sodium sulphate, almost exclusively in the decahydrate, amounts to nearly 5.5 to 6 million tonnes (Mt/a) annually. In 1985, the production was 4.5 Mt/a, which is half from natural sources and a half from chemical production. Whereas, after 2000, at a stable level until 2006, the natural production had tremendously increased to 4 Mt/a, and at the same time chemical production has decreased to 1.5 to 2 Mt/a, with 5.5 to 6 Mt/a as a total. For all the applications, chemically produced and naturally produced sodium sulphate are practically interchangeable.

FAQs (Frequently Asked Questions)

1. What is the appearance of the Glauber’s salt like?

The Glauber’s salt is considered to be the vitreous mineral having a white or the colourless appearance, which is formed by brimes consisting of sodium sulphate as the evaporite. It might also appear to be externally colourless, yellowish-white, greenish-white, or even just plain white. The texture can either be the well-formed crystals or granular having the coarse form. This broadly describes the physical appearance of the Glauber’s salt, also known as sodium sulphate.

2. What are some of the properties of the Glauber’s salt?

The molar mass of Glauber’s salt is 322.2gms/mole and the chemical compound is crystallised in the monoclinic crystal structure. It’s melting point is approximately 32.38 degrees celsius and this compound tends to undergo dehydration when it gets heated in the suitable environments. At standard pressure and temperature, the density of Glauber’s salt is 1.464 grams/cm3. These are some of the properties of Glauber's salt.

3. What are some of the small level and common applications for Glauber's salt?

The decahydrate, or the Glauber’s salt is used as the laxative and it is also utilised for removing some of the drugs from a human body, after an overdose. The compound was proposed as the heat storage concept for passive solar heating panels and systems in 1953. This is because of its properties of high heat of crystallisation and unusual solubility. It is also used for defrosting windows, starch manufacturing, cattle feed, and as an additive in carpet fresheners.

4. What can I expect from the Vedantu notes on “Glauber’s salt”?

You can expect to learn the different aspects and factors associated with Glauber’s salt when you study from the Vedantu notes in this chapter. Some of the different sections covered by Vedantu notes for “Glauber’s salt” includes definition, brief explanation, structure, physical and chemical properties, production, uses, and common queries associated with the topic. This helps the students to understand the concepts related to the chapter so that they can prepare well for the exams. 

5. How can I download the Vedantu notes on “Glauber’s salt”?

For downloading the Vedantu notes on “Glauber’s salt” you have to visit the specific section on the Vedantu website or app. These notes are offered in PDF file format and are available to download for free. You just have to click on the “Download PDF” button, provide the necessary details and your file will be downloaded on your device for offline use whenever you want.

6. What is Galuber's salt used for?

Commonly, Glauber's salt is used in various drugs as a laxative. Besides, to treat a few overdose cases (like paracetamol cases), this compound is specifically useful for eliminating unnecessary body drugs.

7. How does Glauber's salt look like?

Glauber's salt is admitted to be a vitreous mineral with a colourless or white appearance, formed by the brines comprising sodium sulphate as an evaporite. It can also appear externally colourless, greenish-white, yellowish-white, or even white. The texture can be given as either granular, in the coarse form, or the well-formed crystals.

8. Give some Glauber's salt's properties.

Glauber's salt holds a molar mass of 322.2 gms/mole. This chemical compound is also believed to crystallise in a monoclinic crystal structure. It has a melting point, which is roughly equal to 32.38℃. Usually, this compound undergoes dehydration when it is heated in suitable environments. At standard temperature and pressure, the Glauber's salt's density is equal to 1.464 gms/cm3.

9. List the small-scale applications of Glauber's salt?

Glauber's salt, which is a decahydrate, can be used as a laxative. It is more effective for the removal of some drugs such as acetaminophen (paracetamol) from the human body. As an example, after an overdose.

In 1953, this compound was proposed for the heat storage concept in passive solar heating systems. This takes advantage of its properties of unusual solubility and the high heat of crystallisation (78.2 kJ/mol). 

Other uses include starch manufacture, defrosting windows, an additive in carpet fresheners, and cattle feed.