Potassium

Potassium (K), with an atomic mass of 39.098, is the first element in the fourth period of the periodic table. Used for centuries, this alkali metal is generated from potash. It always exists in compounds with other elements and is extremely reactive; it is never found in nature in its pure form..

1.0Introduction

Potassium is an important Group 1 alkali metal in the periodic table, having an atomic number of 19. Potassium is silvery-white and malleable. The metal is constantly immersed in kerosene to prevent oxidation because of its strong reactivity. 

It instantly combines with water to create hydrogen gas, which burns with a lavender flame.It is essential for the proper operation of cells, nerve signals, and muscle contractions.

Sources of Potassium Due to its high reactivity, potassium does not exist in nature in its elemental form. Despite this, sylvite and kainite, the minerals that make up potash, have large amounts of it.

Potassium is a very common element in the earths  crust. Out of the top 10 elements, it is ranked eight. It makes up about 2.1% of the crust of the earth. 

2.0 Physical Properties of Potassium

3.0Chemical Properties of Potassium

• Electronegativity: 0.82 (Pauling scale)
• Density: 0.86 g/cm³ at 0°C
• Van der Waals Radius: 0.235 nm
• Ionic Radius: 0.133 nm
• First Ionization Energy: 418.6 kJ/mol

Reactions of Potassium

• With Air: Potassium quickly tarnishes when exposed to air. It reacts with oxygen to form orange-coloured potassium superoxide (KO₂).

4K+O₂​→2KO_2​

• With Water: Potassium reacts vigorously with water, producing potassium hydroxide (KOH) and hydrogen gas. This exothermic reaction is faster than sodium's but slower than rubidium's.

2K+2H₂​O→2KOH+H₂​

• With Halogens: Potassium reacts vigorously with halogens to form corresponding potassium halides.

K+F₂→2KF (Potassium fluoride)

2K+Cl₂​→2KCl (Potassium chloride)

2K+Br₂​→2KBr (Potassium bromide)

2K+I₂→2KI (Potassium iodide)

• With Acids: Potassium dissolves readily in dilute sulfuric acid, producing potassium ions and hydrogen gas.

2K+H₂SO₄→2K⁺+ SO₄²⁻+H₂

• With Potassium Peroxide: Reacting potassium with potassium peroxide forms potassium oxide.

K₂O₂ + 2K → 2K₂O

4.0Compounds of Potassium  

1. Potassium Chloride (KCl)

Properties: It is a white, crystalline solid highly soluble in water.

2. Potassium Hydroxide (KOH)

Properties: It appears as white pellets or flakes and is highly caustic. It is very soluble in water and produces heat.

3. Potassium Nitrate (KNO₃)

Properties: A white crystalline solid, soluble in water. Known as saltpetre.

4. Potassium Carbonate (K₂CO₃)

Properties: A white salt, hygroscopic, and highly soluble in water.

5. Potassium Permanganate (KMnO₄)

Properties: A dark purple crystalline solid, soluble in water, and a strong oxidising agent.

6. Potassium Dichromate (K₂Cr₂O₇)

Properties: A bright orange crystalline solid, highly soluble in water, and a powerful oxidising agent.

5.0Applications of Potassium

The vital chemical element potassium is used in a wide range of fields. These are some applications for it:

1. Fertilizers: A crucial ingredient for plant growth, potassium increases crop yields and resistance to disease. Restoring soil potassium levels and promoting healthy plant development are two frequent uses for potassium fertilizers, such as potassium chloride (KCl) and potassium sulfate (K₂SO₄).
2. The Food Sector

• Preservatives: Potassium compounds are frequently used to preserve food, such as potassium sorbate and potassium benzoate. They contribute to food preservation by preventing the growth of bacteria, yeasts, and mold.

3. Health:

• Supplemental Information: Potassium is necessary to keep the body functioning normally. It is essential for regulating fluid levels and electrolyte balance, as well as for nerve transmission and muscle contractions. Supplements with potassium cure or

4. Water Treatment: Iron, manganese, and hydrogen sulfide are among the dangerous materials that potassium permanganate (KMnO3) is used to oxidize and remove from water. In water systems, it also aids in minimizing offensive odors and managing biological growth.
5. Metal Hardening: Potassium can be mixed with other metals to create alloys that act as hardening agents, giving the metal greater tensile and wear resistance.
6. Chemical Production: A variety of chemical products, such as soaps, detergents, and biodiesel, are made using potassium hydroxide (KOH), commonly referred to as caustic potash. It serves as both a powerful base and a counterbalance.
7. Aluminum Production: Potassium compounds are employed in a number of metallurgical processes, including the aluminum production process, where they contribute to increased efficiency.