Page 1
p-BLOCK ELEMENTS & THEIR COMPOUNDS
TRENDS IN PROPERTIES OF p-BLOCK ELEMENTS.
B C N O F Ne
Al Si P S Cl Ar
Ga Ge As Se Br Kr
In Sn Sb Te I Xe
Tl Pb Bi Po At Rn
Covalent radius, van der Waals'
radius, enthalpy of atomization
(upto group 14), metallic character
Electronegativity,
enthalpy of atomization
(except for N 2 , O 2 , F 2 ),
ionization enthalpy,
oxidizing power.
Electronegativity,
ionization enthalpy,
oxidizing power.
Covalent radius,
van der Waals'
radius,
metallic character
(A) GROUP 13 ELEMENTS : THE BORON FAMILY
Oxidation state and trends in chemical reactivity :
General Oxidation State = + 3.
Reactivity towards acids and alkalies
2 Al(s) + 6 HCl(aq) ?? ? 2 Al
3+
(aq) + 6 Cl
?
(aq)
+ 3 H
2
(g)
2Al(s) + 2NaOH (aq) + 6H
2
O (1) ?? ? 2Na
+
[Al(OH)
4
]
?
(aq) + 3H
2
(g)
Sodium tetrahydroxoaluminate (III)
Reactivity towards halogens
2E(s) + 3X
2
(g) ? 2EX
3
(s) (X = F, Cl Br, I)
Page 2
p-BLOCK ELEMENTS & THEIR COMPOUNDS
TRENDS IN PROPERTIES OF p-BLOCK ELEMENTS.
B C N O F Ne
Al Si P S Cl Ar
Ga Ge As Se Br Kr
In Sn Sb Te I Xe
Tl Pb Bi Po At Rn
Covalent radius, van der Waals'
radius, enthalpy of atomization
(upto group 14), metallic character
Electronegativity,
enthalpy of atomization
(except for N 2 , O 2 , F 2 ),
ionization enthalpy,
oxidizing power.
Electronegativity,
ionization enthalpy,
oxidizing power.
Covalent radius,
van der Waals'
radius,
metallic character
(A) GROUP 13 ELEMENTS : THE BORON FAMILY
Oxidation state and trends in chemical reactivity :
General Oxidation State = + 3.
Reactivity towards acids and alkalies
2 Al(s) + 6 HCl(aq) ?? ? 2 Al
3+
(aq) + 6 Cl
?
(aq)
+ 3 H
2
(g)
2Al(s) + 2NaOH (aq) + 6H
2
O (1) ?? ? 2Na
+
[Al(OH)
4
]
?
(aq) + 3H
2
(g)
Sodium tetrahydroxoaluminate (III)
Reactivity towards halogens
2E(s) + 3X
2
(g) ? 2EX
3
(s) (X = F, Cl Br, I)
BORON (B):
Some Important Reactions of Boron and its compounds :
Page 3
p-BLOCK ELEMENTS & THEIR COMPOUNDS
TRENDS IN PROPERTIES OF p-BLOCK ELEMENTS.
B C N O F Ne
Al Si P S Cl Ar
Ga Ge As Se Br Kr
In Sn Sb Te I Xe
Tl Pb Bi Po At Rn
Covalent radius, van der Waals'
radius, enthalpy of atomization
(upto group 14), metallic character
Electronegativity,
enthalpy of atomization
(except for N 2 , O 2 , F 2 ),
ionization enthalpy,
oxidizing power.
Electronegativity,
ionization enthalpy,
oxidizing power.
Covalent radius,
van der Waals'
radius,
metallic character
(A) GROUP 13 ELEMENTS : THE BORON FAMILY
Oxidation state and trends in chemical reactivity :
General Oxidation State = + 3.
Reactivity towards acids and alkalies
2 Al(s) + 6 HCl(aq) ?? ? 2 Al
3+
(aq) + 6 Cl
?
(aq)
+ 3 H
2
(g)
2Al(s) + 2NaOH (aq) + 6H
2
O (1) ?? ? 2Na
+
[Al(OH)
4
]
?
(aq) + 3H
2
(g)
Sodium tetrahydroxoaluminate (III)
Reactivity towards halogens
2E(s) + 3X
2
(g) ? 2EX
3
(s) (X = F, Cl Br, I)
BORON (B):
Some Important Reactions of Boron and its compounds :
? Small amines such as NH
3
, CH
3
NH
2
and (CH
3
)
2
NH give
unsymmetrical cleavage of diborane.
B
2
H
6
+ 2NH
3
?? ? [H
2
B (NH
3
)
2
]
+
+ [BH
4
]
?
? Large amines such as (CH
3
)
3
N and pyridine give symmetrical
cleavage of diborane.
2(CH
3
)
3
N + B
2
H
6
?? ? 2H
3
B ?? ? N(CH
3
)
3
? B
2
H
6
+ 2CO ? ? ? ? ? ? ? ?
atm 20 , C º 200
2BH
3
CO (borane carbonyl)
(B) GROUP 14 ELEMENTS : THE CARBON FAMILY
Carbon (C), silicon (Si), germanium (Ge), tin (Sn) and lead (Pb) are the
members of group 14.
Electronic Configuration = ns
2
np
2
.
Oxidation states and trends in chemical reactivity
Common oxidation states = +4 and +2. Carbon also exhibits negative
oxidation states. In heavier members the tendency to show +2 oxidation
state increases in the sequence Ge < Sn < Pb.
(i) Reactivity towards oxygen :
All members when heated in oxygen form oxides. There are mainly two
types of oxides, i.e. monoxide and dioxide of formula MO and MO
2
respectively.
(ii) Reactivity towards water :
Tin decomposes steam to form dioxide and dihydrogen gas.
(iii) Reactivity towards halogen :
These elements can form halides of formula MX
2
and MX
4
(where X = F, Cl
Br, I). Stability of dihalides increases down the group.
Page 4
p-BLOCK ELEMENTS & THEIR COMPOUNDS
TRENDS IN PROPERTIES OF p-BLOCK ELEMENTS.
B C N O F Ne
Al Si P S Cl Ar
Ga Ge As Se Br Kr
In Sn Sb Te I Xe
Tl Pb Bi Po At Rn
Covalent radius, van der Waals'
radius, enthalpy of atomization
(upto group 14), metallic character
Electronegativity,
enthalpy of atomization
(except for N 2 , O 2 , F 2 ),
ionization enthalpy,
oxidizing power.
Electronegativity,
ionization enthalpy,
oxidizing power.
Covalent radius,
van der Waals'
radius,
metallic character
(A) GROUP 13 ELEMENTS : THE BORON FAMILY
Oxidation state and trends in chemical reactivity :
General Oxidation State = + 3.
Reactivity towards acids and alkalies
2 Al(s) + 6 HCl(aq) ?? ? 2 Al
3+
(aq) + 6 Cl
?
(aq)
+ 3 H
2
(g)
2Al(s) + 2NaOH (aq) + 6H
2
O (1) ?? ? 2Na
+
[Al(OH)
4
]
?
(aq) + 3H
2
(g)
Sodium tetrahydroxoaluminate (III)
Reactivity towards halogens
2E(s) + 3X
2
(g) ? 2EX
3
(s) (X = F, Cl Br, I)
BORON (B):
Some Important Reactions of Boron and its compounds :
? Small amines such as NH
3
, CH
3
NH
2
and (CH
3
)
2
NH give
unsymmetrical cleavage of diborane.
B
2
H
6
+ 2NH
3
?? ? [H
2
B (NH
3
)
2
]
+
+ [BH
4
]
?
? Large amines such as (CH
3
)
3
N and pyridine give symmetrical
cleavage of diborane.
2(CH
3
)
3
N + B
2
H
6
?? ? 2H
3
B ?? ? N(CH
3
)
3
? B
2
H
6
+ 2CO ? ? ? ? ? ? ? ?
atm 20 , C º 200
2BH
3
CO (borane carbonyl)
(B) GROUP 14 ELEMENTS : THE CARBON FAMILY
Carbon (C), silicon (Si), germanium (Ge), tin (Sn) and lead (Pb) are the
members of group 14.
Electronic Configuration = ns
2
np
2
.
Oxidation states and trends in chemical reactivity
Common oxidation states = +4 and +2. Carbon also exhibits negative
oxidation states. In heavier members the tendency to show +2 oxidation
state increases in the sequence Ge < Sn < Pb.
(i) Reactivity towards oxygen :
All members when heated in oxygen form oxides. There are mainly two
types of oxides, i.e. monoxide and dioxide of formula MO and MO
2
respectively.
(ii) Reactivity towards water :
Tin decomposes steam to form dioxide and dihydrogen gas.
(iii) Reactivity towards halogen :
These elements can form halides of formula MX
2
and MX
4
(where X = F, Cl
Br, I). Stability of dihalides increases down the group.
ANOMALOUS BEHAVIOUR OF CARBON :
Catenation :
The order of catenation is C > > Si > Ge ? Sn. Lead does not show
catenation. Due to the property of catenation and p?-p? bonds formation,
carbon is able to show allotropic forms.
Bond Bond enthalpy (kJ mol
?1
) Bond Bond enthalpy (kJ mol
?1
)
C?C 348 Si??Si 297
Ge?Ge 260 Sn?Sn 240
Allotropes of Carbon
Diamond :
Crystalline lattice sp
3
hybridisation and linked to four other carbon atoms
by using hybridised orbitals in tetrahedral manner. The C?C bond length is
154 pm. and produces a rigid three dimensional network of carbon atoms.
Graphite :
Graphite has layered structure. Layers are held by van der Waal?s forces
and distance between two layers is 340 pm. Each layer is composed of
planar hexagonal rings of carbon atoms. C ? C bond length within the
layer is 141.5 pm. Each carbon atom in hexagonal ring undergoes sp
2
hybridisation graphite conducts electricity along the sheet. Graphite cleaves
easily between the layers and therefore, it is very soft and slippery. For
this reason graphite is used as a dry lubricant in machines running at high
temperature.
Fullerenes :
C
60
molecule has a shape like soccer ball and called
Buckminsterfullerene. It contains twenty six -membered rings and twelve
five membered rings. This ball shaped molecule has 60 vertices and each
one is occupied by one carbon atom and it also contains both single and
double bonds with C ? C distance of 143.5 pm and 138.3 pm respectively.
Page 5
p-BLOCK ELEMENTS & THEIR COMPOUNDS
TRENDS IN PROPERTIES OF p-BLOCK ELEMENTS.
B C N O F Ne
Al Si P S Cl Ar
Ga Ge As Se Br Kr
In Sn Sb Te I Xe
Tl Pb Bi Po At Rn
Covalent radius, van der Waals'
radius, enthalpy of atomization
(upto group 14), metallic character
Electronegativity,
enthalpy of atomization
(except for N 2 , O 2 , F 2 ),
ionization enthalpy,
oxidizing power.
Electronegativity,
ionization enthalpy,
oxidizing power.
Covalent radius,
van der Waals'
radius,
metallic character
(A) GROUP 13 ELEMENTS : THE BORON FAMILY
Oxidation state and trends in chemical reactivity :
General Oxidation State = + 3.
Reactivity towards acids and alkalies
2 Al(s) + 6 HCl(aq) ?? ? 2 Al
3+
(aq) + 6 Cl
?
(aq)
+ 3 H
2
(g)
2Al(s) + 2NaOH (aq) + 6H
2
O (1) ?? ? 2Na
+
[Al(OH)
4
]
?
(aq) + 3H
2
(g)
Sodium tetrahydroxoaluminate (III)
Reactivity towards halogens
2E(s) + 3X
2
(g) ? 2EX
3
(s) (X = F, Cl Br, I)
BORON (B):
Some Important Reactions of Boron and its compounds :
? Small amines such as NH
3
, CH
3
NH
2
and (CH
3
)
2
NH give
unsymmetrical cleavage of diborane.
B
2
H
6
+ 2NH
3
?? ? [H
2
B (NH
3
)
2
]
+
+ [BH
4
]
?
? Large amines such as (CH
3
)
3
N and pyridine give symmetrical
cleavage of diborane.
2(CH
3
)
3
N + B
2
H
6
?? ? 2H
3
B ?? ? N(CH
3
)
3
? B
2
H
6
+ 2CO ? ? ? ? ? ? ? ?
atm 20 , C º 200
2BH
3
CO (borane carbonyl)
(B) GROUP 14 ELEMENTS : THE CARBON FAMILY
Carbon (C), silicon (Si), germanium (Ge), tin (Sn) and lead (Pb) are the
members of group 14.
Electronic Configuration = ns
2
np
2
.
Oxidation states and trends in chemical reactivity
Common oxidation states = +4 and +2. Carbon also exhibits negative
oxidation states. In heavier members the tendency to show +2 oxidation
state increases in the sequence Ge < Sn < Pb.
(i) Reactivity towards oxygen :
All members when heated in oxygen form oxides. There are mainly two
types of oxides, i.e. monoxide and dioxide of formula MO and MO
2
respectively.
(ii) Reactivity towards water :
Tin decomposes steam to form dioxide and dihydrogen gas.
(iii) Reactivity towards halogen :
These elements can form halides of formula MX
2
and MX
4
(where X = F, Cl
Br, I). Stability of dihalides increases down the group.
ANOMALOUS BEHAVIOUR OF CARBON :
Catenation :
The order of catenation is C > > Si > Ge ? Sn. Lead does not show
catenation. Due to the property of catenation and p?-p? bonds formation,
carbon is able to show allotropic forms.
Bond Bond enthalpy (kJ mol
?1
) Bond Bond enthalpy (kJ mol
?1
)
C?C 348 Si??Si 297
Ge?Ge 260 Sn?Sn 240
Allotropes of Carbon
Diamond :
Crystalline lattice sp
3
hybridisation and linked to four other carbon atoms
by using hybridised orbitals in tetrahedral manner. The C?C bond length is
154 pm. and produces a rigid three dimensional network of carbon atoms.
Graphite :
Graphite has layered structure. Layers are held by van der Waal?s forces
and distance between two layers is 340 pm. Each layer is composed of
planar hexagonal rings of carbon atoms. C ? C bond length within the
layer is 141.5 pm. Each carbon atom in hexagonal ring undergoes sp
2
hybridisation graphite conducts electricity along the sheet. Graphite cleaves
easily between the layers and therefore, it is very soft and slippery. For
this reason graphite is used as a dry lubricant in machines running at high
temperature.
Fullerenes :
C
60
molecule has a shape like soccer ball and called
Buckminsterfullerene. It contains twenty six -membered rings and twelve
five membered rings. This ball shaped molecule has 60 vertices and each
one is occupied by one carbon atom and it also contains both single and
double bonds with C ? C distance of 143.5 pm and 138.3 pm respectively.
SOME IMPORTANT REACTIONS OF CO, CO
2
AND METAL
CARBIDES :
? CLASSIFICATION OF SILICATES :
(A) Orthosilicates :
(B) Pyrosilicate :
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