Phosphorus – Occurrence, Properties, Uses, Effects

Phosphorus is an essential element for life, primarily through phosphates, which are compounds containing phosphate ion. Phosphates are a component of DNA, RNA, ATP, and phospholipids, all of which are complex compounds that are essential to cells. Human urine was the initial supply of phosphate, and bone ash was an important early source of phosphate. Because phosphate is present in fossilized deposits of animal remains and excreta, phosphate mines contain fossils. Low phosphate levels are a significant growth constraint in some aquatic systems. The bulk of phosphorus compounds extracted are used to make fertilizers.

Although phosphorus exists in two major forms, white phosphorus and red phosphorus, it is never found as a free element on Earth due to its high reactivity. It has a concentration of about one gram per kg in the Earth’s crust. Phosphorus is most commonly found in minerals as phosphate.

Phosphorus is a chemical element with the atomic number 15 and the symbol P. 

Occurrence of Phosphorus

• The concentration of phosphorus in the Earth’s crust is approximately one gram per kg. It is not found in nature in its pure form but is found in a variety of minerals, most notably as phosphates.
• Today, the primary commercial source of this element is inorganic phosphate rock, which contains some apatite.
• Urine, bone ash, and guano were historically major organic sources, but economic success was limited.
• Because urine contains phosphorus, it has to fertilise properties that are still used today.

Properties of Phosphorus

• Phosphorous is a nitrogen-group multivalent nonmetal. It is found in nature in several allotropic forms and is required for organisms to live.
• There are three types of phosphorous: white, red, and black phosphorous, though their colours are more likely to differ slightly.
• White phosphorous is the industrial variety; it glows in the dark, is spontaneously flammable when exposed to air, and is a lethal poison.
• Because of slight variations in its chemical structure, red phosphorous can range in colour from orange to purple.
• The third form, black phosphorous, is produced under high pressure, resembles graphite, and, like graphite, can conduct electricity.

Oxidation State of Phosphorus

• Phosphorus, like nitrogen, can have oxidation states of +3 or 3, depending on the electronegativity of the elements with which it combines.
• The primary distinction between nitrogen and phosphorus is that the latter has significantly lower electronegativity and larger atoms with outer d orbitals available.
• For these reasons, the similarities between nitrogen and phosphorus chemistry are mostly formal, masking the actual, significant differences.
• Phosphorus’ outer d orbitals allow for octet expansion, leading to the +5 state, in which five real covalent bonds are created in compounds, a condition that nitrogen cannot attain.

Uses of Phosphorus

• Nowadays, four types of phosphorous are commonly used: white, black, red, and violet.
• Phosphorus is easily located on the periodic table at position fifteen, just below nitrogen (N).
• Phosphorus can also be found in fireworks, fertilizers, and baking powder.
• Phosphorus is also utilised in steel manufacturing.
• Phosphates are also used in the manufacture of fine china and special glasses.

Health Effects of Phosphorus

Phosphates are the most common form of phosphorus in the environment. Because phosphorus is a component of DNA and aids in energy delivery, it is a vital chemical in the human body. Phosphates are also found in a lot of plants.

Humans have significantly altered the natural phosphate supply by adding phosphate-rich manure to the soil and using phosphate-containing detergents. Phosphates are also found in a variety of foods, including cheese, sausages, and hams. Too much phosphate can harm your health by causing kidney damage and osteoporosis. Phosphate shortages are also possible. They are caused by long-term use of the medication. Phosphate deficiency is harmful to our health.

In its pure form, phosphorus is white. White phosphorus is the most dangerous phosphorus source we know of. When white phosphorus occurs naturally, it can be dangerous to our health. White phosphorus is extremely toxic and can be fatal in many cases.

Allotropes Of Phosphorus

In nature, there are various allotropic forms of phosphorus. White phosphorus, black phosphorus, and red phosphorous are the most important allotropic forms of phosphorus.

White Phosphorus

White phosphorus molecules have a tetrahedral structure and are made up of four atoms. Ring strain and instability are caused by the tetrahedral arrangement. The molecule is said to be made up of six single P–P bonds. There are two crystalline forms known. The alpha form is defined as the element’s standard state, but it is actually metastable under standard conditions.

Red Phosphorus

Phosphorus in the form of red phosphorus is a frequent allotrope that is assumed to be a derivative of the P₄ molecule. It is made up of phosphorus atoms in an amorphous (non-crystalline) network. It has been discovered to be more stable than white phosphorus (another naturally occurring phosphorus allotrope). The deep red colour and powdery texture of red phosphorus distinguish it. The white phosphorus allotrope gradually transforms into the red phosphorus allotrope. This transformation is accelerated in the presence of light and energy in the form of heat. When white phosphorus is partially converted into red phosphorus, it takes on a distinctive yellow appearance.

Sample Questions

Question 1: What is the purpose of the element phosphorus?

Answer:

Phosphorus is an essential plant nutrient, and phosphate compounds primarily use it in the production of fertilizers. There is a phosphorus cycle, just as there are bio carbon and nitrogen cycles. Phosphorus is used in the production of red phosphorus safety matches, pyrotechnics, and inflammatory shells.

Question 2: What are the main sources of phosphorus?

Answer:

Phosphorus is found in high concentrations in protein foods such as milk and milk products, as well as meat alternatives such as beans, lentils, and nuts. Phosphorus is found in grains, particularly whole grains. Phosphorus is found in lower concentrations in vegetables and fruits.

Question 3: What makes phosphorus unique?

Answer:

Except for black phosphorus, phosphorus is a poor conductor of heat and electricity. At room temperature, all forms of phosphorus are stable. The white allotrope (also known as yellow phosphorus) is similar to wax, the red and purple allotropes are non-crystalline solids, and the black allotrope is similar to graphite in pencil lead.

Question 4: What is red phosphorus?

Answer:

Red phosphorus is a common allotrope of phosphorus and is thought to be a derivative of the P₄ molecule. It is made up of phosphorus atoms in an amorphous (non-crystalline) network. It has been discovered to be more stable than white phosphorus.

Question 5: Which phosphorus is used in matchstick?

Answer:

When you light the match, a small amount of red phosphorus on the striking surface is transformed to white phosphorus, which then ignites. The heat from this ignites the potassium chlorate, causing the match head to burst into flame.