Potassium Carbonate Formula – Structure, Properties, Uses, Sample Questions

Potassium (K) is a chemical element and its atomic number is 19. Potassium is a silvery-white metal that sifts enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. Carbon (C) is a chemical element and the atomic number is 6 in the periodic table. It is nonmetallic and has four electrons available to form covalent chemical bonds. Carbon is about 0.025 per cent of Earth’s crust. Oxygen (O) is the chemical element with atomic number 8 in the periodic table. It is a highly reactive nonmetal and an oxidant that readily forms oxides with most elements as well as with other compounds. 

What is Potassium Carbonate?

Potassium Carbonate is a chemical inorganic compound that consists of Potassium cation (K⁺) and Carbonate (CO^2-₃) anion with the chemical formula K₂CO₃. It is an inorganic salt that is used in the manufacturing of soaps, detergents, glass, and fertilizers to increase the yield, as a baking agent, and to treat hard water. It is also called Carbonate of Potash or dipotassium carbonate or pearl ash, Salt of Wormwood, and Salt of Tartar.

It is a hygroscopic, deliquescent powder that is white in color and it does not have any odour. It is soluble in water and insoluble in ethanol. It is found in natural hollows together with different carbonates.

The chemical formula of Potassium Carbonate is K₂CO₃.

Structure of Potassium Carbonate

The structure has two potassium cations (K⁺) and carbonate anion (CO^2-₃). It is a precious stone that is found at temperatures underneath  – 47 ºC.

Preparation of Potassium Carbonate

• It is prepared by potash in an oven and a white powder is obtained which is potassium carbonate. Potassium Carbonate is prepared when Potassium Chloride (KCl) and Magnesium Oxide (MgO) react with the Carbon Dioxide (CO₂) to form MgCO₃.KHCO₃.4H₂O, which is also known as Engel’s Salt. This salt is then decomposed and calcined to produce Potassium Carbonate (K₂CO₃).

KCl + MgO + CO₂  →  MgCO₃.KHCO₃.4H₂O

• Potassium Chloride is reacted with carbon dioxide (CO₂) to give Potassium Bicarbonate (KHCO₃) in the presence of an organic amine. The Potassium Bicarbonate is further calcined to get Potassium Carbonate. 

2KHCO₃  →  K₂CO₃ + H₂O + CO₂

• It is prepared by treating potassium hydroxide with carbon dioxide,

2KOH + CO₂  →  K₂CO₃ + H₂O

Properties of Potassium Carbonate

• The molecular weight of K₂CO₃ is 138.205 g/mol.
• It is a white, hygroscopic strong with and deliquescent appearance. 
• Its density is 2.43 g m/L and its melting point is 891 ºC. 
• It is soluble in water and is insoluble in methanol, ethanol, and acetone.
• It has structures of solid soluble base arrangements when soluble in water and the structure of carbonate anion is the second anion species that begin from the deprotonation of carbonic corrosive H₂CO₃.

Uses of Potassium Carbonate

• It is used in the manufacturing of soaps, detergents, glass, and fertilizers to increase the yield, as a baking agent, and to treat hard water.
• It is used as a gentle drying detergent.
• It is used for the production of grass jelly.
• It is used to create Dutch procedure chocolate by alkalization.
• It is used in the generation of wire.
• It is used as an essential raw material in the production of materials in industries like chemical, light and medicine.

Sample Questions

Question 1: Is Potassium Carbonate soluble in water? 

Answer:

Yes it is soluble in water. When potassium carbonate is dissolved in water the potassium and carbonate ions are dissociates.

Question 2: Why potassium carbonate is called pearl ash?

Answer: 

It is the primary component of potash and the refined pearl ash or salts. Pearl ash is prepared by baking the potash in a solution to remove impurities. Then the fine white powder obtained is the pearlash.

Question 3: What is the color of Potassium Carbonate?

Answer: 

Potassium carbonate is a basic medium solution. It is normally white in colour and basic solutions turn the colour of phenolphthalein solutions into pink.

Question 4: What happens when potassium carbonate is reacted with hydrochloric acid?

Answer: 

When potassium carbonate is reacted with hydrochloric acid it produces potassium chloride, carbon dioxide and water. 
K₂CO₃+2HCl→2KCl+CO₂+H₂O

Question 5: Is Potassium carbonate base or acid?

Answer:

Potassium carbonate is a base which more soluble in water and it is used in the process of saponification in which it  neutralize the fatty acids to soaps. 

Question 6: What are the health hazards of Potassium Carbonate?

Answer: 

It is a non-combustible compound When it comes in contact with skin, eyes, and respiratory tract can cause irritation. It can cause severe abdominal pain, diarrhea, chest pain, rapid drop in blood pressure, vomiting.