Allotropes of Sulphur-Rhombic sulphur (α-sulphur), Monoclinic sulphur (β-sulphur), Colloidal Sulphur, Physical & Chemical Properties of Sulphur

Sulphur

The element sulphur, often known as sulfur, is one of the most reactive elements in the periodic table. It is a non-metal that belongs to the periodic table’s group 16 (VI A). 

The elemental sulphur is a crystalline solid with a vivid yellow colour at room temperature. The element sulphur is prevalent throughout the universe. Sulfur has been used by humans since the dawn of time. Brimstone, which means “firestone,” was the name given to it in the past.

Physical Properties of Sulphur

  1. When found naturally, sulphur has a yellowish colour and is frequently found as a crystal.
  2. At room temperature, sulphur is non-reactive. Sulfur or sulphur can combine to form a variety of polyatomic molecules.
  3. S8, also known as octa-sulfur, is one of the most common sulphur molecules. It is a soft, odourless solid with a bright yellow colour. This molecule has a melting point of 115.21 degrees Celsius and a boiling point of 444.6 degrees Celsius. When this molecule is between its melting and boiling points, it polymerizes, resulting in increased viscosity but lower density.
  4. Depolymerization occurs at higher temperatures, resulting in decreased viscosity.
  5. Depending on the allotrope, the density varies.
  6. All stable sulphur allotropes do not allow electricity to pass through them. As a result, they are excellent electrical insulators.

Chemical Properties of Sulphur

  1. Sulfur combustion produces a blue flame and an unpleasant odour due to the formation of sulphur dioxide.
  2. Sulfur is insoluble in water but slightly soluble in nonpolar organic solvents such as benzene.
  3. This element’s most common oxidation states are +4 and +6.
  4. Sulfur is highly reactive and almost all elements react with it, including iridium, which is highly unreactive except for noble gases.
  5. Sulfur compounds have many unusual properties, including the ability to catenate in the same way that carbon does.
  6. Sulphur’s properties allow it to form chain structures as well as a ring system, similar to carbon.
  7. One of the most well-known sulphur compounds is hydrogen sulphide (H2S). It is a colourless, poisonous gas that smells like rotten eggs. It is naturally present in mineral water and volcanoes as vapours. A large amount of hydrogen sulphide is produced during the sulphur removal process from petroleum.
  8. Sulfur and oxygen can also combine to form a variety of compounds. Sulfur dioxide, a poisonous and colourless gas, is the most well-known sulphur oxide.
  9. In addition, it is used as a reducing agent and bleach in a variety of industries. It was also used by scientists to produce sulphur trioxide. This oxide is also beneficial in the ripening of fruits and the preservation of food.

Uses of Sulphur

  • Sulfur is required for the synthesis of other essential chemicals. Sulfuric acid, the most important chemical produced by sulphur, has numerous industrial applications.
  • The reaction of sulphur with methane produces carbon disulfide, which is required for the production of rayon and cellophane.
  • Another important application of sulphur is in the vulcanization of rubber.
  • Organosulfur compounds are found in a wide range of pharmaceutical products. It is also found in a variety of agrochemicals and dyestuffs.
  • Since ancient times, people have used elemental sulphur as pesticides and fungicides. Dusting sulphur (powdered sulphur) is a common pesticide used in organic farming.
  • Sulfur plays an important role in the body and is required for the synthesis of certain proteins. Sulfur, for example, is required for the synthesis of glutathione, which acts as a powerful antioxidant to protect your cells from damage.
  • While sulphur found in foods is beneficial to the body, there is little evidence that taking sulphur supplements is beneficial.
  • Sulfur is an FDA-approved ingredient for use in over-the-counter dandruff products. It is frequently used in conjunction with salicylic acid. However, there is limited evidence to support that use.
  • Sulfur supplements are frequently used to treat osteoarthritis.
  • When used topically, sulphur may be safe. Sulfur-containing products containing up to 10% sulphur have been used safely in clinical studies lasting up to eight weeks.

Allotropes of Sulphur

Sulphur generates a number of allotropes. The first is yellow rhombic sulphur (α-sulphur), and the second is monoclinic sulphur (β-sulphur). The most intriguing feature is that the allotropes of the sulphur compound are interconvertible in terms of thermal stability. It means that rhombic sulphur produces monoclinic sulphur when heated above 369K.

Rhombic sulphur (α-sulphur)

Rhombic sulphur is a crystalline substance with an octahedral shape. When we heat the roll sulphur solution in the CS2, we get rhombic sulphur. It has a yellow colour, a specific gravity of 2.06, and a melting point of 385.8K. Rhombic sulphur compounds are not soluble in water, but they are soluble in ether, benzene, or alcohol.

Monoclinic sulphur (β-sulphur)

When we melt rhombic sulphur in a dish and cool it, we get monoclinic sulphur. In this process, we poke two holes in the crust and pour out the remaining liquid. When the crust is removed after this process, we get colourless needle-shaped crystals of -sulphur.

Colloidal Sulphur

It is created by passing hydrogen sulphide through a saturated and cooled sulphur dioxide solution in water. The other method is to mix an alcohol and sulphur solution into the water. It also serves as a solvent in the carbon disulfide reaction. It can be used in pharmaceuticals.

Sample Questions (FAQs)

Question 1: What are the three common uses of sulfur?

Answer:

It is used in the production of automobile batteries, fertiliser, oil refining, water treatment, and mineral extraction. Other uses for sulfur-based chemicals include rubber vulcanization, bleaching paper, and the manufacture of products such as cement, detergents, and pesticides.

Question 2: How does one get sulfur naturally?

Answer:

Sulfur is extracted from natural gas, coal, crude oil, and other sources such as flue dust and gases produced during the processing of metal sulphide ores. Elemental sulphur can be obtained in a variety of forms, such as sulphur flowers, fine crystalline powder, and roll sulphur.

Question 3: What is the Biological Role of the Sulphur?

Answer:

Sulphur is an important component of every living cell. It is found in equal amounts in the human body as potassium. The majority of sulphur in plants and animals is found in the form of amino acids. Eggs are heavy in sulphur, which helps chicks’ feathers grow. The smell of decaying eggs is caused by hydrogen sulphide production. Sulfur’s role in the cell is to decrease hydrogen and its electrons, allowing for cellular repair.

Question 4: What are some chemical properties of sulphur?

Answer:

Due to the creation of sulphur dioxide, burning sulphur generates a blue flame and a disagreeable odour. Sulfur is water insoluble but somewhat soluble in non-polar organic solvents such as benzene. This element’s most prevalent oxidation states are +4 and +6. Except for noble gases, sulphur is highly reactive and almost reacts with all elements, including iridium, which is rather unreactive.

Question 5: What is octa-sulphur?

Answer:

S8, also known as octa-sulfur, is a sulphur molecule. It’s a spongy, odourless solid with a bright yellow colour. This molecule polymerizes when it is between its melting and boiling temperatures, resulting in increased viscosity but lower density.

Er. Neeraj K.Anand is a freelance mentor and writer who specializes in Engineering & Science subjects. Neeraj Anand received a B.Tech degree in Electronics and Communication Engineering from N.I.T Warangal & M.Tech Post Graduation from IETE, New Delhi. He has over 30 years of teaching experience and serves as the Head of Department of ANAND CLASSES. He concentrated all his energy and experiences in academics and subsequently grew up as one of the best mentors in the country for students aspiring for success in competitive examinations. In parallel, he started a Technical Publication "ANAND TECHNICAL PUBLISHERS" in 2002 and Educational Newspaper "NATIONAL EDUCATION NEWS" in 2014 at Jalandhar. Now he is a Director of leading publication "ANAND TECHNICAL PUBLISHERS", "ANAND CLASSES" and "NATIONAL EDUCATION NEWS". He has published more than hundred books in the field of Physics, Mathematics, Computers and Information Technology. Besides this he has written many books to help students prepare for IIT-JEE and AIPMT entrance exams. He is an executive member of the IEEE (Institute of Electrical & Electronics Engineers. USA) and honorary member of many Indian scientific societies such as Institution of Electronics & Telecommunication Engineers, Aeronautical Society of India, Bioinformatics Institute of India, Institution of Engineers. He has got award from American Biographical Institute Board of International Research in the year 2005.