22.8+The+Other+Group+5A+Elements-+P,+As,+Sb,+and+Bi

= The Other Group 5A Elements =

Phosphorus, arsenic, antimony, and bismuth are known as **The Other Group 5A Elements**. (Nitrogen is apparently too selfish to share a section with them.) The entire Group 5A elements are known as the **pnictogens**. A few general characteristics of these elements are:
 * They have an oxidation state of -3
 * They commonly obtain an octet of electrons through covalent bonding
 * Their electron configurations follow the general form //ns// ﻿2 //np// //﻿//3 (//n// represents the energy level for each element respectively)

**Occurance, Isolation, and Properties of Phosphorus**!
Phosphorus is commonly found in the form of phosphate minerals. The main source of phosphorus is phosphate rock in the form of Ca 3 (PO 4 ) 2. It is produced commercially by reduction of calcium phosphate with carbon in the presence of SiO 2 : The phosphorus produced in this reaction is the allotrope known as white phosphorus, which can spontaneously burst into flames if exposed to air. When heated to 400 o C it is converted to a more stable allotrope known as red phosphorus, which does not burst into flames when exposed to air. "Safety" matches contain red phosphorus which can be easily converted to white phosphorus by friction.

**Halides**
Phosphorus forms numerous compounds with halogens and the most important are the trihalides and the pentahalides. Phosphorus trichloride (PCl 3 ) is the most significant of these compounds because it is used to prepare many products such as soaps, detergents, plastics, and insecticides.

**Oxy Compounds of Phosphorus**
The most significant compounds of phosphorus are those in which phosphorus is combined in some way with oxygen. Two common compounds are [|Phosphoric Acid](H 3 PO 4 ),also called orthophosphoric acid, and [|Phosphorous Acid](H 3 PO 3 ). These acids have a tendency to undergo condensation reactions when heated. **Condensation reactions** are reactions in which a small molecule (such as a molecule of water) is split out from between two reacting molecules. Example: Two H 3 PO 4 molecules are joined by the elimination of one H 2 O molecule to form H 4 P 2 O 7. Click [|here] for the animation!

Helpful link(s)

 * [|Quizzes over the whole chapter]

Fun Section
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