Group – 15 elements Chemistry Notes
Elements of Group.15 :
→ Group -15 of the extended or long form of periodic table consists of five elements: Nitrogen (N), Phosphorus (P), Arsenic (As), Antimony (Sb) and Bismuth (Bi).
→ These five elements are collectively known as nitrogen family or pnicogens i.e., suffocation creating. The compounds of these elements are known as pniconide. In this family the first two members are non-metals, the next two are metalloids and the last member i.e., Bismuth (Bi) is a metal.
- Non metals : Nitrogen (N), Phosphorus (P)
- Metalloids : Arsenic (As), Antimony (Sb)
- Metal : Bismuth (Bi) .
→ Nitrogen, the first member of the family occurs in free state in atmosphere which contains 78% of nitrogen by volume.
→ In the combined state, it is the major constituent of proteins which are present in both plants and animals. It is also an important constituent of amino acids and nucleic acids. Various compounds like potassium nitrate (salt peter), ammonia, ammonium chloride, sodium nitrate (chile salt peter), compounds of ammonia, urea, fertilizers also contain nitrogen.
→ Phosphorus is very reactive element so it does not occur in free state. In combined state it is found in the form of various minerals, compounds etc. Major amount of phosphorus occurs in apatites, which are minerals. Some important minerals of phosphours are listed below:
- Phosphorite – Ca3 (PO4)2
- Fluorapatite – 3Ca3(PO4)2 CaF2 or 2Ca5 (PO4)3F
- Chlorapatite – 3Ca3(PO4) . CaCl2 or 2Ca5(PO4)3Cl
- Hydrogapatite – 3Ca3(PO4 )3 . Ca(OH)2 or 2Ca5(PO4)3OH
→ Phosphorus constitutes our bones, teeth, brain, muscles and nerve tissues. In milk, eggs, fish, beans its present as phosphoproteins, Except these phosphorus is also found in phosphate fertilizers, Adenosine triphosphate ATP), Adenosine diphosphate ADP), in DNA and RNA (in which phosphorus is present as polyester chains of phosphates).
Rest elements i.e.,As, Sb and Bi of this family are not much abundant.