Bài 7. Nitơ

Chapter 8

Table of Contents

1. Introduction
2. Occurrence
3. Chemical properties
4. Compounds
5. Uses

Nitrogen family


1. Nitrogen family. Introduction

Chapter 8

Placement in the periodic table

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Chapter 8

1. Nitrogen family. Introduction

Placement in the periodic table, continued

Nitrogen

Phosphorus

Arsenic

Antimony

Bismuth

14
7N

31

75

15P

33As

122

51Sb

209

83Bi


Chapter 8

1. Nitrogen family. Introduction

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.


Chapter 8

1. Nitrogen. Introduction

Placement in the periodic table, continued














Isotopes:

14
15
7N and 7N

Earth`s crust abundance: 0.002 %
2 2 3
Electron configuration: 1s 2s 2p
0
Melting point: -210.1 C
0

Boiling point: -195.8 C
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


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



Forms diatomic structure (N2) and inactive element

14
15
N and 0.36% of N


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.


Chapter 8

2. Nitrogen . Occurrence.

Occurrence.

Nitrogen
Nitrogenisisaa basic
basicelement

elementin
in living
living organisms
organismsas
aswell
wellas
asititisisused
usedin
inthe
the production
productionof
of DNA
DNA and
and
fertilizers.
fertilizers.ItItisisfound
foundin
inliving
livingorganisms
organismsas
asbuilding
buildingstone
stonein
innucleic
nucleicacids,
acids,in
inproteins
proteinsand
andvitamins
vitaminsby

by
15%.
15%.


2. Nitrogen . Occurrence.

Chapter 8
Preparation.
Preparation in laboratory:

1.
1.Heating
Heating the
the mixture
mixture of
ofNaNO
NaNO22and
andsaturated
saturatedNH
NH44Cl
Clgives
givespure
pureNN22gas.
gas.
NaNO
NaNO22(aq)
(aq)++NH
NH44Cl(aq)
Cl(aq)→

→NaCl(aq)
NaCl(aq)++2H
2H22O(l)
O(l)++NN22(g)
(g)

2.
2.CO
CO22must
mustbe
beremoved
removedfrom
fromthe
the air
airsample
sample by
bypassing
passing ititthrough
through aaconcentrated
concentratedbase
basesolution.
solution.
2NaOH(aq)
2NaOH(aq)++CO
CO22(g)
(g)→
→ Na
Na22CO
CO33(aq)
(aq)++HH22O(g)

O(g)
The
The air
airisisthen
thenreacted
reacted with
with hot
hotcopper
copperpowder.
powder.Oxygen
Oxygenin
inair
airisisfiltered
filteredby
byforming
formingcopper
copper(II)
(II)oxide.
oxide.
2Cu(s)
2Cu(s)++(3N
(3N22++O
O22)) →
→ 2CuO(s)
2CuO(s)++2N
2N22(g)
(g)


2. Nitrogen . Occurrence.

Chapter 8
Preparation.
Preparation in laboratory:

3.
3.Decomposition
Decomposition of
of sodium
sodiumazide,
azide,NaN
NaN33or
orbarium
barium azide,
azide,Ba(N
Ba(N33))22
2NaN
2NaN33(s)
(s)→
→2Na(s)
2Na(s) ++3N
3N22(g)
(g)

This
Thisreaction
reaction isisapplied
appliedin
in the
the air-bag

air-bagof
of automobiles.
automobiles.


Chapter 8

2. Nitrogen . Occurrence.

Preparation.
Preparation in industry:


The
Themain
mainsource
sourceof
of NN22isisthe
theair
airand
andititisisobtained
obtained by
byfractional
fractionaldistillation
distillation of
of liquified
liquifiedair
airin
inindustry.
industry.

Nitrogen
Nitrogenevaporates
evaporatesfirst
firstduring
duringthe
thedistillation.
distillation.


Because
Becausethe
theboiling
boilingpoint
pointof
of oxygen
oxygen isis-183°C
-183°Cand
andthe
theboiling
boilingpoint
pointof
of nitrogen
nitrogenisis-196°C
-196°C


Chapter 8

2. Nitrogen . Occurrence.

Chapter 8

2. Nitrogen . Occurrence.


Chapter 8

2. Nitrogen . Occurrence.


Chapter 8

3. Nitrogen . Chemical prop.

Nitrogen
Nitrogen may
maytake
takeall
alloxidation
oxidation numbers
numbersbetween
between-3
-3and
and+5.(:N
+5.(:N N:)
N:)Bond
Bondbetween
betweenNNatoms
atomsisisvery

very
strong
strongthat
thatisiswhy
whyNN22does
doesnot
notreact
reactwith
withacids,
acids,bases,
bases,water
waterand
andhalogens.
halogens.

1. At high temperatures, it reacts with active metals.
6Na + N2 → 2Na3N
0
2. At 300 atm. pressure and 500 C temperature , nitrogen gas react with H 2 .(Haber method).
N2 + 3H2 → 2NH3

0
3. At 2500 C or in high electrical current (lightning).
N2 + O2 → 2NO


4. Nitrogen . Compounds.

Chapter 8

a) Ammonia – NH3









Colorless gas
Sharp smell
Lower density than air
0
Boiling point is -33.4 C
0
Freezing point is -77.8 C
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

1.

React with acids and give salts.
NH3+ HCl → NH4Cl

2.

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.


0
A colorless liquid with 5.2 g/ml of density. Melting point is -42 C and the boiling point is
0
82.6 C. 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
2NO + O2
3NO2 + H2O

4NO + 6H2O
Pt

2NO2
2HNO3 + NO


Production of Nitric Acid


Nitric Acid (HNO3)

Lightning may cause to form nitric
acid.

Do you afraid

May be

acid rain

of

rain

Lightning may cause to form nitric
acid.