The document discusses the chemical properties of various p-block elements. It describes how elements within the groups react with substances like oxygen, hydrogen, halogens and metals. For example, it notes that aluminum burns in air if powdered, reacts with chlorine, and does not react with alkalis like sodium hydroxide at moderate temperatures. It also summarizes the reactions of group 13 (boron forms trihalides), group 14 (carbon remains unreactive with air), group 15 (nitrogen reacts with hydrogen to form ammonia), group 16 (oxygen readily forms compounds with most elements), group 17 (halogens react with hydrogen to form hydrogen halides) and group 18 elements (noble gases

1. Chemical Properties Of
P-block Elements
MOOMNA FAHEEM

2. P Block elements
The elements in which valence
electron are enter in p sub shell are
known as p block elements.
The p block elements is the region
of periodic table that include group
13 to group 18 and does not
include He .

3. GROUP 13 ELEMENTS (ICOSAGENS)
 The chemical properties of group 13 elements reflect the increasingly
metallic character down the group.
 The elements of group 13 are :
1. Boron
2. Aluminum
3. Gallium
4. Indium
5. Thallium

4. Boron :
 Boron is chemically unreactive except at high temperatures .
 Finally divided boron burn in air to form oxides and nitride:
2B +2O2 → 2B2O3 (oxides)
2B + N2 → 2BN (nitride)
 Accordingly in halogen boron form trihalides
2B + 2X3 → 2BX3
 Boron does not react with acid like HCl and HF but powdered boron reacts with
concentrated HNO3 ( nitric acid ) .

5. …
 Reactivity towards alkali : the boron is unreactive when come in
contact with alkali at moderate temperature..
B + NaOH → NO REACTION

6. Aluminum
 Aluminum undergo following reactions :
 Reactivity toward air : Aluminum burns in air if it is in powdered form .
Other wise , aluminum form a thin layer of oxide which make it unreactive to other
substances. Amorphous aluminum when reacted with air by providing heat form Al2O3 .
2Al +302 → 2Al2O3
 Reaction with chlorine :
Aluminum reacts with chlorine by passing dry chlorine over a heated aluminum foil .
2Al +3Cl2 → 2AlCl3

7. Group 14 Elements : (crystalogens )
 Group 14 elements are :
1. Carbon
2. Silicon
3. Germanium
4. Tin
5. lead

8. Carbon :
 Carbon under go following reactions :
 Reaction with air :
carbon remains unreactive with air at ordinary temperature . A strong
heating carbon is converted into co and co2 .
2C + O2 → 2CO
2C + 2O2 → 2CO2
 Formation of carbides :
when carbon is heated in the presence of CaO ,calcium carbide
is obtained.
CaO + 3C →CaC2 + CO

9. …
 Reaction with water :
Water has no reaction on carbon but steam reacts when passed
over a red hot carbon to form water gas .(co and h 2 ) .
C + H2O → CO + H2
 Reaction with hydrogen :
when hydrogen is pass through carbon heated at the temperature
of electric arc , acetylene is formed .
2C + H2 → C2H2

10. Silicon :
 Silicon undergo following reactions :
 Reaction with air :
Silicon burns in air on heating to form silicon dioxide .
Si + O2 → SiO2
 Reaction with alkali :
Silicon get dissolved in alkalies liberating hydrogen .
Si +2NaOH + H2O →Na2SiO3 + 2H2

11. …
 Reaction with halogens :
Silicon reacts with fluorine only directly . Chlorine , bromine and
iodine do not directly react with it .
Si + 2F2 → SiF4
 Reaction with water :
Silicon does not reacts with water at ordinary temperature but react with
steam to give oxide .
Si + 2H2O → SiO2 + 2H2

12. Group 15 Elements : (Pnictogens)
 The elements of group 15 are :
1. Nitrogen
2. Phosphorus
3. Arsenic
4. Antimony
5. Bismuth
6. Moscovium

13. Nitrogen :
 Nitrogen undergo following reactions :
 Reaction with hydrogen :
Nitrogen reacts with H2 at about 6000C under pressure in the
presence of catalyst .
N2 + 3H2 → 2NH3 ( +141 KJ ∕ mol ).
 Reaction with oxygen :
Nitrogen reacts with oxygen only in the presence of electric
spark . Reaction of nitrogen and oxygen also take place in the atmosphere at the time of
lightning produce by the charged clouds .
N2 + O2 → 2NO ( -180 KJ ∕ mol ).

14. …
 Reaction with metals :
Metals such as Mg , Li and Al , etc reacts with nitrogen to form nitrides .
N2 + 3Mg → Mg3N2
N2 + 2Al → 2AlN
N2 + 6Li → 2Li3N
 Reaction with calcium carbide
When calcium, carbide is heated at about 1000 C in presence of N2, Calcium Cyanamide is
formed.
CaC2+N2→CaCN2+C

15. Phosphorus
Phosphorus undergo following reaction
 Reaction with oxygen :
White phosphorus react with oxygen at 35-45 C but Red phosphorus doesn’t react
with O2 below 240 C
P4+3O2→P4O6
P4+5O2→P4O10
 Reaction with Alkalis :
Alkalis react with white phosphorus to liberate phosphine gas.
Red phosphorus doesn’t react under these conditions.
P4+3O2+3NaOH→PH3+3NaH2PO2

16. …
 Reaction with Halogens
Phosphorus react with Halogens to form PX3. F2 react more quickly.
P4+6X2→ 4PX3
 Reaction with Hydrogen
Phosphorus doesn’t react with H2 in elementary state.

17. Group 16 Element (Chalcogens)
 The element of group 16 are .
1. Oxygen
2. Sulfur
3. Selenium
4. Tellurium
5. polonium

18. Oxygen
 Oxygen is highly reactive non metallic element.
As it readily formed compound with almost all other elements.
 Reaction with Hydrogen
Oxygen react with hydrogen to form water (H20) and hydrogen peroxide (H2O2) .
2H2 + O2 → 2H20
H2 + O2 → H2O2
 Reaction with Group1 element
 Oxygen react with group1 element readily.
4Li+O2→2Li2O3
4Na+O2→2Na2O
With other alkali metals M+O2→MO2

19. …
 Reaction with group2 Elements
 Alkaline earth metal also react with oxygen, though not as rapidly as group1 metals.
 These reaction also required heat.
2M+O2→2MO
Where M Represent Be, Mg , Ca , Sr , Ba and Ra.

20. Group 7 Elements ( Halogens)
 The element of 7 group are
1. Fluorine
2. Chlorine
3. Bromine
4. Iodine
5. astatine

21. Chemical reaction of Halogen
 The most important reaction of halogens are
 Reaction with Hydrogen
All halogen react with halogen under different condition to give Hydrogen Halides.
H2+X2→2HX ( X= HALOGENS )
 Reaction with Oxygen
Halogen formed number of oxides.
Fluorine react with oxygen at high voltage discharge.
Other in cold and hot state to form different salts of oxyacid.

22. …
Cl2+2NaOH→NaCl + NaClO + H2O
Br2+2NaOH→NaBr+ NaBrO + H2O
I2+NaOH→NaI+HIO
 Reaction with H2S
Halogen oxidize H2S to liberate free sulfur .
X2+H2S→2HX+S

23. Group 8 Elements ( Noble Gases)
 The group 8 elements are
1. Helium
2. Neon
3. Argon
4. Krypton
5. Xenon
6. Radon

24. …
 Noble Gases have low chemical reactivity.
 The full valence electron shells of these atoms make noble gases extremely stable and
unlikely to form chemical bonds because they have little tendency to gain or lose
electrons.