Bài 7. Nitơ

Nitrogen is very important for living organisms, exist in construction of proteins and nucleic acids... Nitrogen is a basic element in living organisms as well as it is used in the prod

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147N

3115P

7533As

20983BiArsenic

Placement in the periodic table, continued

Common oxidation numbers are - 3,+1,+2,+4 and +5

Metallic character increases from top to bottom

N and P are nonmetals, As and Sb are metalloid, Bi is a metal

All have allotropes, except N and Bi

Phosphorus has white, red and black allotropes

Nitrogen is very important for living organisms, exist in construction of proteins and nucleic acids

 Common oxidation number: -3,-2,-1,0,+1,+2,+3,+4,+5

 Physical state: gas

 Colour: colourless

 Discovery date: 1772

 Discoverer: Daniel Rutherford

 Discovery place: Scotland

Placement in the periodic table, continued

Placement in the periodic table, continued

 Has two names One "azot", meaning "dead" in Latin, was given by Lavoisier, other, "nitrogen", means "nitrate former"

 Little soluble and lighter than air

 Isotopes have 99.64% of 14N and 0.36% of15N

 Forms diatomic structure (N2) and inactive element

Percentage of N2 gas in the atmosphere is 78% by volume and 75% by mass

Found in compounds in the earth's crust at a rate of only 0.002% by mass

Mineral sources of nitrogen are

Potassium nitrate (Saltpeter) – KNO3

Sodium nitrate (Chile saltpeter) – NaNO3

Nitrogen is a basic element in living organisms as well as it is used in the production of DNA and fertilizers It is found in living organisms as building stone in nucleic acids, in proteins and vitamins by 15%.

Nitrogen is a basic element in living organisms as well as it is used in the production of DNA and fertilizers It is found in living organisms as building stone in nucleic acids, in proteins and vitamins by 15%

Occurrence.

1 Heating the mixture of NaNO2 and saturated NH4Cl gives pure N2 gas.

NaNO2(aq) + NH4Cl(aq) → NaCl(aq) + 2H2O(l) + N2(g)

2 CO2 must be removed from the air sample by passing it through a concentrated base solution

2NaOH(aq) + CO2(g) → Na2CO3(aq) + H2O(g)

The air is then reacted with hot copper powder Oxygen in air is filtered by forming copper (II) oxide

2Cu(s) + (3N2 + O2 ) → 2CuO(s) + 2N2(g)

1 Heating the mixture of NaNO2 and saturated NH4Cl gives pure N2 gas

NaNO2(aq) + NH4Cl(aq) → NaCl(aq) + 2H2O(l) + N2(g)

2 CO2 must be removed from the air sample by passing it through a concentrated base solution

2NaOH(aq) + CO2(g) → Na2CO3(aq) + H2O(g)

The air is then reacted with hot copper powder Oxygen in air is filtered by forming copper (II) oxide

2Cu(s) + (3N2 + O2 ) → 2CuO(s) + 2N2(g)

Preparation.

Preparation in laboratory:

3 Decomposition of sodium azide, NaN3 or barium azide, Ba(N3)2

2NaN3(s) → 2Na(s) + 3N2(g)

This reaction is applied in the air-bag of automobiles

3 Decomposition of sodium azide, NaN3 or barium azide, Ba(N3)2

2NaN3(s) → 2Na(s) + 3N2(g)

This reaction is applied in the air-bag of automobiles

Preparation.

Preparation in laboratory:

The main source of N2 is the air and it is obtained by fractional distillation of liquified air in industry

Nitrogen evaporates first during the distillation

Because the boiling point of oxygen is -183°C and the boiling point of nitrogen is -196°C

The main source of N2 is the air and it is obtained by fractional distillation of liquified air in industry

Nitrogen evaporates first during the distillation

Because the boiling point of oxygen is -183°C and the boiling point of nitrogen is -196°C

Preparation.

Preparation in industry:

Nitrogen may take all oxidation numbers between -3 and +5.(:N N:) Bond between N atoms is very strong that is why N2 does not react with acids, bases, water and halogens.

Nitrogen may take all oxidation numbers between -3 and +5.(:N N:) Bond between N atoms is very strong that is why N2 does not react with acids, bases, water and halogens

1 At high temperatures, it reacts with active metals

4 Good reducing agent

2NH3+ 3CuO → 2Cu+ N2+3H2O

A colorless liquid with 5.2 g/ml of density Melting point is -42 0C and the boiling point is 82.6 0C When metallic nitrate heated with concentrated sulfuric acid NaNO3(s) + H2SO4(aq) NaHSO4(aq) + HNO3(aq)

Nitric acid is the third most important industrial acid (after sulfuric and phosphoric acid) It is used to prepare fertilizers, explosives, nylon and plastics.

Nitric acid is commercially produced by the Ostwald process.

4NH3 + 5O2 4NO + 6H2O 2NO + O2 2NO2

3NO2 + H2O 2HNO3 + NO

Pt

Lightning may cause to form nitric

Reactants Al, Fe, Cr, Ni

Condition

Concen- trated and

heted Concen- trated

Gas products

NO or N2O N2O or N2

Reactants Pb, Cu, Hg, Ag

Condition

Concen- trated and

heted Concen- trated

Gas products

NO or N2O N2O or N2

Au, Pt

In any concen- tration

No product

*metallurgy *explosive *dye *paper *textile *medicine

*fertilizers *to

*production of ammonia *inert atmosphere

*manufacture of hardware

ammonia

quickly it is accepted that it is one of the most

powerful poison used by people