Bài 7. Nitơ

Chapter 8
Nitrogen family
Introduction
Occurrence
Chemical properties
Compounds
Uses
Table of Contents
Chapter 8
1. Nitrogen family. Introduction
Placement in the periodic table
12251Sb
147N
3115P
7533As
20983Bi
Arsenic
Nitrogen
Phosphorus
Antimony
Bismuth
Placement in the periodic table, continued
Chapter 8
1. Nitrogen family. Introduction
Placement in the periodic table, continued
Chapter 8
1. Nitrogen family. Introduction
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.
Chapter 8
1. Nitrogen. Introduction
Isotopes: 147N and 157N
Earth`s crust abundance: 0.002 %
Electron configuration: 1s2 2s2 2p3
Melting point: -210.10C
Boiling point: -195.80C
Density: 0.00125 g/l
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
Chapter 8
1. Nitrogen . Introduction
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
Chapter 8
2. Nitrogen . Occurrence.
Occurrence.
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%.
Chapter 8
2. Nitrogen . Occurrence.
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)
Chapter 8
2. Nitrogen . Occurrence.
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.
Chapter 8
2. Nitrogen . Occurrence.
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
Chapter 8
2. Nitrogen . Occurrence.
Preparation.
Preparation in industry:
Chapter 8
2. Nitrogen . Occurrence.
Chapter 8
2. Nitrogen . Occurrence.
Chapter 8
2. Nitrogen . Occurrence.
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.
Chapter 8
3. Nitrogen . Chemical prop.
1. At high temperatures, it reacts with active metals.
6Na + N2 → 2Na3N
2. At 300 atm. pressure and 500 0C temperature , nitrogen gas react with H2 .(Haber method).
N2 + 3H2 → 2NH3
3. At 2500 0C or in high electrical current (lightning).
N2 + O2 → 2NO
Chapter 8
4. Nitrogen . Compounds.
a) Ammonia – NH3
Colorless gas
Sharp smell
Lower density than air
Boiling point is -33.4 0C
Freezing point is -77.8 0C
Very high solubility in water
Weak base
Preparation in Industry: Prepared by Haber Process
N2 + 3H2 → 2NH3
Preparation in Laboratory:
NH4Cl + NaOH → NaCl + H2O + NH3
Chapter 8
4. Nitrogen . Compounds.
a) Ammonia – NH3
Haber, Fritz (1868-1935), German chemist and Nobel laureate, best known for his development of an economical method of ammonia synthesis.
Chapter 8
4. Nitrogen . Compounds.
a) Ammonia – NH3
Reactions of Ammonia
React with acids and give salts.
NH3+ HCl → NH4Cl
Forms ammonium hydroxide in water.
NH3 + H2O → NH4OH
3. React with pure oxygen.
4NH3 + 3O2 → 2N2+ 6H2O
4. Good reducing agent.
2NH3+ 3CuO → 2Cu+ N2+3H2O
Chapter 8
4. Nitrogen . Compounds.
Chapter 8
4. Nitrogen . Compounds.
Chapter 8
4. Nitrogen . Compounds.
Nitric Acid(HNO3)
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 (HNO3)
Nitric acid is commercially produced by the Ostwald process.
4NH3 + 5O2 4NO + 6H2O
2NO + O2 2NO2
3NO2 + H2O 2HNO3 + NO
Pt
Production of Nitric Acid
Nitric Acid (HNO3)
Lightning may cause to form nitric acid.
Lightning may cause to form nitric acid.
Do you afraid of rain
May be acid rain
Reactions of Nitric acid some metals
Reactions of Nitric acid
Reactions of Nitric acid
Reactions of Nitric acid
Uses of N2
*metallurgy *explosive *dye *paper *textile *medicine *fertilizers. *to keep frozen foods *production of ammonia *inert atmosphere *manufacture of hardware
ammonia
Because Nicotine like cyanide show its effect quickly it is accepted that it is one of the most powerful poison used by people.