ANS:C - phosphorous

Heating a mixture of phosphate rock, coke, and sand in an electric furnace typically produces phosphorus. The process involves the reduction of phosphate rock (which is mainly fluorapatite, Ca5(PO4)3F) with carbon (from coke) to produce elemental phosphorus vapor, along with carbon monoxide gas. This process is commonly known as the electric furnace method or the thermal process for phosphorus production. The chemical reaction involved in this process can be represented as follows: 2𝐶𝑎5(𝑃𝑂4)3𝐹+10𝐶+10𝑆𝑖𝑂2→10𝐶𝑎𝑆𝑖𝑂3+10𝐶𝑂+𝑃42Ca5(PO4)3F+10C+10SiO2→10CaSiO3+10CO+P4 In this reaction, phosphate rock reacts with carbon and silicon dioxide (from sand) to produce calcium silicate slag (CaSiO3), carbon monoxide (CO), and elemental phosphorus (P4). The elemental phosphorus vapor is then collected and condensed into a liquid form, which can be further processed to produce various phosphorus-based chemicals, including phosphoric acid and phosphate fertilizers. However, the direct product of heating the mixture in an electric furnace is elemental phosphorus, not phosphoric acid or other phosphate compounds. Phosphorus is a chemical element with the symbol P and atomic number 15. It is a non-metallic element that is essential for life, as it plays crucial roles in biological processes, such as DNA and RNA synthesis, energy transfer (through ATP), and bone formation. Here's an explanation of key aspects of phosphorus:

1. Physical Properties: Phosphorus exists in several allotropic forms, the most common of which are white phosphorus, red phosphorus, and black phosphorus. White phosphorus is a waxy, transparent solid that glows in the dark and is highly reactive. Red phosphorus is a less reactive and more stable form, often used in safety matches and in the production of phosphorus-based chemicals. Black phosphorus has a layered structure and exhibits semiconductor properties.
2. Chemical Properties: Phosphorus readily forms compounds with other elements, particularly oxygen, forming various phosphorus oxides (such as phosphorus pentoxide, P2O5) and phosphoric acids (such as orthophosphoric acid, H3PO4). These compounds are important in industry, agriculture, and biological systems.
3. Biological Importance: Phosphorus is an essential nutrient for all living organisms. It is a key component of nucleic acids (DNA and RNA), where it forms the phosphate backbone that carries genetic information. Phosphorus is also present in ATP (adenosine triphosphate), a molecule that stores and transfers energy within cells. Additionally, phosphorus is a component of phospholipids, which are structural molecules found in cell membranes.
4. Industrial Applications: Phosphorus and its compounds have numerous industrial applications. Phosphoric acid is used in the production of fertilizers, detergents, and food additives. Phosphorus-based flame retardants are used in plastics and textiles. Phosphorus is also important in the production of steel, where it is used as an alloying agent to improve the strength and corrosion resistance of steel.
5. Environmental Impact: Phosphorus pollution can occur from agricultural runoff, wastewater discharges, and industrial processes. Excess phosphorus in water bodies can lead to eutrophication, where excessive algal growth depletes oxygen levels, harming aquatic ecosystems. Efforts to mitigate phosphorus pollution include improved agricultural practices, wastewater treatment, and phosphorus recycling.