Magnesium

Magnesium ranks as the eighth most abundant element in the Earth's crust and the third most prevalent element dissolved in seawater, playing a crucial role in both geological processes and biological systems. With an atomic number of 12, magnesium contains 12 protons and 12 electrons. It is situated in the third period and Group 2 of the periodic table, classifying it as an alkaline earth metal. This group is characterised by its high reactivity and strong tendency to form compounds, making magnesium a vital element in many chemical and industrial processes.

1.0Introduction

Magnesium is a strong, lightweight, silvery-white metal. When exposed to air, it also creates a protective oxide coating that stops corrosion, just like aluminium. Magnesium dust, on the other hand, can catch fire in the atmosphere. 

It is alloyed with other metals in the aerospace sector and beyond to make materials lighter and easier to weld. Magnesium also plays a vital role in medicine, appearing in forms such as magnesium hydroxide, sulfate, chloride, and citrate.

2.0Physical properties of Magnesium   

Property

Value

Symbol

Mg

Atomic Number

12

Atomic Mass

24.305

Appearance

Silvery-white, solid state

Density

1.738 grams per cubic centimetre

Melting Point

650°C

Boiling Point

1091°C

Density:

1.738 g/cc

Oxidation states:

2

Other Properties

Lightweight yet strong

3.0Chemical Properties of magnesium 

Magnesium's high reactivity is key, making it vital in numerous chemical processes and applications. Its ability to react with various elements and compounds, flammability, and reactions with water and acids emphasises its significance in industrial and biological applications.

Here’s a detailed explanation of its fundamental chemical properties:

  1. High Flammability
  • Magnesium is acutely combustible and readily catches fire when it comes into contact with heat or flame. Because magnesium oxide forms as it burns, it emits a white flare and a dazzling white light. The combustion reaction can be represented as: 

2Mg (s) + O2(g) → 2MgO (s)

  • This property makes magnesium useful in applications such as flares, fireworks, and pyrotechnics, where a bright light is needed.
  1. Reactivity with Oxygen
  • Magnesium oxide (MgO)is formed when magnesium reacts with oxygen, producing a white, powdery oxide layer. This reaction occurs at high temperatures and can be represented as:

2Mg (s) + O2(g) → 2MgO (s)

  • Despite magnesium's strong reactivity, the oxide layer that forms on it protects against corrosion.
  1. Reactivity with Water
  • Hot Water Reaction: Magnesium reacts rapidly with hot water, producing magnesium hydroxide (Mg(OH)₂) and hydrogen gas (H₂). The reaction can be represented as 

Mg (s) + 2H2O (l) → Mg(OH)2(aq) + H2(g)

  • Cold Water Reaction: Magnesium reacts slowly with cold water, often forming a self-protective layer of magnesium hydroxide that inhibits further reaction. Thus, the reaction is much less vigorous compared to hot water.
  1. Combining with Non-Metals

Formation of Compounds: Magnesium reacts with non-metals such as sulfur, phosphorus, and nitrogen to form various compounds. For example:

  • With Sulfur: When magnesium and sulfur react, magnesium sulfide is formed.

(MgS): Mg (s) +S(s) → MgS(s)

  • With Phosphorus: When magnesium and phosphorus react, magnesium phosphide (Mg₃P₂) forms.

3Mg (s) +P2 (s) → Mg3P2(s)

  • With Nitrogen: Magnesium can react with nitrogen at high temperatures to form magnesium nitride (Mg₃N₂).
  1. Reactivity with Acids

Acid Reactions: Magnesium reacts with various acids to produce magnesium salts and hydrogen gas. For example:

  • With Hydrochloric Acid: Mg (s)+2HCl (aq)→MgCl2(aq)+H2(g)
  • With Sulfuric Acid: Mg (s)+H2SO4(aq)→MgSO4(aq)+H2(g)

4.0Uses of Magnesium 

Magnesium is widely used in many applications and is often used in compound form. Some of the most common uses of magnesium include:

  • Lightweight Products: Magnesium produces lightweight items such as laptops, luggage, car seats, and power tools.
  • Fireworks and Flares: Metal is utilized in fireworks, sparklers, and flares because it ignites easily in the air and burns with a bright, white light.
  • Explosives and Pyrotechnics: Magnesium is essential in explosive and pyrotechnic devices due to its high reactivity.
  • Drying Processes: Magnesium is often used in compound form as a mordant in drying processes.
  • Fire-Retardant Plastics: Magnesium hydroxide is added to plastics to produce fire-retardant materials. It is also used as a supplement in cattle feed.
  • Heat-Resistant Bricks: Magnesium oxide is utilized to produce heat-resistant bricks for furnaces.
  • Photosynthesis: Magnesium is vital in the biological world, especially in enabling the process of photosynthesis in plants.
  • Human Health: Magnesium is an essential mineral in the human body, playing a key role in enzyme function and maintaining bone health.
  • Medicinal Uses: Medicine uses magnesium to treat skin conditions and address magnesium deficiencies.
  • Aerospace Industry: Magnesium alloys are commonly used in the aerospace industry for their lightweight strength.

Frequently Asked Questions

Many methods extract magnesium from mineral resources, brine, and seawater. It can take a while to isolate something; getting it in complex form is common.

Because it is present in so many different compounds, magnesium is a common and abundant metal used in many applications. These compounds display the qualities of the separate elements that make them up, frequently resulting in improved qualities above the individual element. Magnesium is therefore thought to be among the most amazing elements ever found in science. Significant improvements in subsequent experiments and discoveries have been made possible by its discovery.

Magnesium is used in lightweight products (e.g., laptops, luggage, car seats), fireworks, explosives, fire retardant plastics, and heat-resistant bricks. It is also important in the aerospace industry in the form of alloys.

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