34. SUBGROUP OF NITROGEN.

The subgroup of nitrogen includes элементы:азот, phosphorus, arsenic, antimony, bismuth.

STAY IN THE NATURE

Content in crust: nitrogen - 0,01%, phosphorus - 0,08%, arsenic - 0,0006%, antimony - 0,0004%, bismuth - 0,00002%

Properties of the V-A elements of subgroup.

Element	Nitrogen N	Phosphorus Р	Arsenic As	Antimony Sb	Bismuth Bi
Property
Order number of element	7	15	33	51	83
Relative atomic mass	14,007	30,974	74,922	121,75	208,980
Temperature of melting, C0	- 210	44,1 (white)	817 (4 MPas)	631	271
Temperature of boiling, C0	- 196	280 (white)	613	1380	1560
G/cm3 density	0,96 (firm)	1,82 (white)	5,72	6,68	9,80
Oxidation levels	+5, +3,-3	+5, +3,-3	+5, +3,-3	+5, +3,-3	+5, +3,-3

Allotropy of phosphorus.

ALLOTROPIC MODIFICATIONS OF PHOSPHORUS.
Property	White phosphorus	Scarlet phosphorus	Black phosphorus
Coloring	White	From red to violet	Gray-black
Smell	Garlick	Has no	Has no
Hardness	Waxy	Firm	Rather soft
Nature of modification	Nonmetallic		Metal
Melting temperature, 0C	44	Melt only under excessive pressure; higher than 280 0s pass into steam of white phosphorus
Sublimating temperature, 0C	60	> 400	> 400
G/cm3 density	1,82	2,36	2,70
Solubility	It is not enough in H2O, it is good in CS2	Insoluble
Reactivity	High	Low	Average
Luminescence	Is	No	No

Receiving nitrogen and phosphorus.

nitrogen	phosphorus
1. In the industry - fractionation of liquid air (tkip O2=-183 0C, N2=-196) 2. In laboratory decomposition of ammonium nitrite when heating NH4NO2=N2+2H2O	2Ca3(PO4) +10C+6SiO2=10CO+CaSiO3+P4

Chemical properties of nitrogen and phosphorus.

nitrogen	phosphorus
1. Interaction with oxygen
N2+O2=2NO (el.duga, 3000 0C)	4P+5O2=2P2O5
2. Interaction with alkali and alkaline earth metals 6Li+N2=2Li3N	2. With halogens 2P+5Cl5=2PCl5
3. With hydrogen 3N2+3H2 2NH3	3. With active metals 2P+3Mg=Mg3P2 (phosphide)
	4. With strong oxidizers 3P+5HNO3+2H2O=3H3PO4+5NO

The major connections.

nitrogen	phosphorus
Ammonia: NH3 nitric acid: HNO3 nitraty:kno3, NaNO3	Phosphoric acid: H3PO4 oxide of phosphorus (V): P2O5 salt phosphates.

Other elements of subgroup: arsenic, antimony, bismuth

   

 

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