K_2 SO_4

Introduction

Potassium sulphate is an inorganic compound with the other name sulphate of potash is an important chemical compound with many applications, especially in fertilizers.

In the 14th century itself, potassium sulphate was known. Tachenius, Glauber, and Boyle are the first to study this chemical compound. It is a salt that is a combination of an acidic and basic compound. Christopher Glaser, a pharmaceutical chemist prepared it and used this for chemical applications, making it named Glaser's salt. It is especially a synthesized chemical, the mineral form is very rare, and arcanite is the mineral of potassium sulphate. A process similar to the Leblanc process is used for the production of potassium sulphates which involves the reaction of potassium chloride and sulphuric acid.

What is Potassium sulphate?

Potassium sulphate is a non-flammable white, transparent, and crystalline chemical with high solubility in water. The chemical composition of potassium sulphate is K₂ SO₄. So, it contains potassium and sulphate ions. And due to this reason, it is widely used as a fertilizer for plants. Potassium sulphate is commonly a synthetic chemical, but some minerals are also present in rare amounts. Salt lakes and volcanic lava also contain the natural version of this compound.

Production of Potassium sulphate

Potassium sulphate can be produced by several methods. Some of the methods are discussed below.

• The method involves the use of sulphuric acid and potassium chloride for the preparation of potassium sulphate. Potassium bisulphate is produced first by the reaction of potassium chloride and sulphuric acid. The reaction is exothermic and involves the production of hydrogen chloride.

  $$\mathrm{KCl + H_2 SO_4 → HCl + KHSO_4 }$$

  The produced potassium sulphate further reacts with potassium chloride to produce potassium sulphate. This is an endothermic reaction that also involves the production of hydrogen chloride.

  $$\mathrm{KCl + KHSO_4 → HCl + K_2 SO_4}$$

• The reaction of potassium hydroxide with sulphuric acid also produces potassium sulphate.

  $$\mathrm{H_2 SO_4 + KOH →K_2 SO_4 + H_2 O}$$

• The direct reaction of potassium and sulphuric Acid also produces potassium sulphate.

  $$\mathrm{2K + H_2 SO_4 →K_2 SO_4 + H_2}$$

• The reaction of sulphuric acid and potassium bicarbonate also produces potassium sulphate.

  $$\mathrm{2KHCO_3 + H_2 SO_4 → K_2 SO_4 + 2H_2 O + 2CO}$$

Properties of Potassium sulphate K₂ SO₄

Potassium sulphate is a very important inorganic compound and is because of its characteristic properties. Some properties of potassium sulphates are tabulated below.

Properties	Value
Symbol	K2 SO4
Appearance	White solid.
Molar mass	174.259 g/mol
Odour	No odour
Solubility	Highly soluble in water but slightly in glycerol.
Melting point	1342 degrees Fahrenheit
Density	2.66 g/cm3
Boiling point	1962 degrees Fahrenheit
Taste	Bitter salty taste.
Solubility in ethanol	Insoluble

Potassium sulphate Structure K₂ SO₄

The crystalline structure of potassium sulphates is common, β-K₂ SO₄. But heating at a relatively high temperature also involves the conversion of β-K₂ SO₄ to α-K₂ SO₄. The temperature required is 583 °C. This is the crystalline structure and is very complex. Potassium sulphate generally consists of two ions such as potassium and sulphate ions. The sulphate ions consist of a tetrahedral geometry and the two ions of potassium surround it. The structure of potassium sulphate is,

Reactions of Potassium sulphate

Potassium sulphate is an important inorganic compound with several applications. So the reactivity of this chemical compound is also very high. Some of the reactions of this chemical compound are pointed out below.

• Potassium sulphate is an inorganic compound with high solubility in water. The reaction of potassium sulphates with water results in the formation of potassium and sulphuric acid. That is,

  $$\mathrm{2K_2 SO_4 + 2H_2 O → 4K + 2H_2 SO_4 + O_2}$$

• Potassium sulphate, K_2 SO_4 is a strong electrolyte. So complete dissociation is present in the case of potassium sulphates. It will undergo dissociation as,

  $$\mathrm{K_2 SO_4 → 2K^+ + SO_4^{2-}}$$

• The reaction of potassium sulphates with hydrogen chloride results in the formation of potassium chloride. That is,

  $$\mathrm{2HCl (aq) + K_2 SO_4 (aq) → H_2 SO_4 (aq) + 2KCl (aq)}$$

• The reaction of potassium sulphates with sulphuric acid results in the formation of KHSO₄, potassium bisulphate.

• They behave like sulphuric acid when heated over a hundred degrees of Celsius. Silicates, titanates, etc. are formed by heating it. Therefore, potassium sulphates are used as a disintegrating agent in the analytical chemistry field.

K₂SO₄ Uses

There are many applications for potassium sulphate. Some of the applications are pointed out below.

• It is rich in potassium and sulphur, so it is widely used as a fertilizer for the soil.

• In the glass manufacturing industry, potassium sulphate is used.

• It is used in the soda blasting process because of its toughness.

• It is used in the medical field as an osmotic laxative.

• It is used in pyrotechnics by combining with potassium nitrate and will produce a purple flame.

• As a salt substitute potassium sulphate is used.

• In animal feed, it is used as a supplement.

• For the preparation of potassium aluminium sulphate, potassium sulphate is used.

• In the manufacture of gypsum cement, potassium sulphate is used.

• As a flash suppressant potassium sulphate is used.

Conclusion

Potassium sulphate is one of the important inorganic chemical compounds with many applications in the chemistry field. It is a white transparent and crystalline compound with no smell. The presence of sulphur and potassium makes it useful as a good fertilizer. The structure of potassium sulphates is β-K₂ SO₄. It is very soluble in water and produces potassium when dissolved in water. Potassium sulphate can be obtained by several chemical processes; the most common method is the reaction of potassium chloride and sulphuric acid.

FAQs

1. What will Potassium sulphate do in plants?

Potassium sulphate as a fertilizer for plants acts as a rich source of potassium. Potassium is an essential nutrient needed for many functions such as starch synthesis, enzyme activation, protein synthesis, water flow regulation, etc. There are many potassium-containing fertilizers available but these may cause insufficient sulphur in plants, but potassium sulphate overcomes this since it contains a good amount of sulphur too.

2. Is potassium sulphate harmful to your health?

Exposure of skin to potassium sulphate will irritate the skin. Irritation to the eyes will also cause when someone gets exposed. This chemical will cause breathing problems and shortness of breath. So, this chemical is toxic to humans.

3. Is K₂ SO₄ an acid or a base?

It is a salt obtained by the reaction of a strong base, potassium chloride, and hydroxide and strong acid, sulphuric acid. It is neither an acid nor a base. So K₂ SO₄ is a neutral chemical compound with a pH value of 7.

4. Is K₂ SO₄ an ionic or covalent compound?

In K₂ SO₄ the potassium in the +1-oxidation state and sulphate in the -2-oxidation together makes an ionic compound. But in the sulphate ion itself the bond present between the non-metallic sulphur and oxygen is covalent. That is the potassium ions are held together with the help of an ionic bond while in the sulphate ions covalent bond is present.

5. Is potassium sulphate used for the purification of water?

Potassium aluminium sulphate, alum, is used in the purification of water.