p-block Elements (Group 13 and 14) Practice Questions - DPP for JEE

 Page 1


1. (b) In Boric acid each B atom is sp
2
 hybridized and contains BO
units which are held together  by hydrogen bonds.
2. (c) AlCl
3
 exists as a dimer (Al
2
Cl
6
). It is a strong Lewis acid as it has
an incomplete octet and has a tendency to gain electrons. AlCl
3
undergoes hydrolysis easily and forms an acidic solution.
AlCl
3
 + 3H
2
O ? Al(OH)
3
 + 3HCl
Option (c) is true that AlCl
3
 sublimes at 180ºC.
3. (c) The IE
1
 of Ga is more than that of Al because of the small atomic
size and greater effective nuclear charge of Ga.
4. (d) Ceramics are inorganic , non-metallic, solid minerals. They come
in a variety of forms, including silicates (silica, SiO
2
 with metal
oxides), oxides (oxygen and metals), carbides (carbon and metals),
aluminates (alumina, Al
2
O
3
 with metal oxides) and nitrides.
The given ceramics are B
4
C (carbides), SiC (carbides), Si
3
N
4
 (nitrides)
and  thus, none of these is an oxide. All of these are non-oxide
ceramics.
5. (b) Because they react with water to form methane gas
Al
4
C
3  
+   12H
2
O –––? 4 Al(OH)
3
 + 3CH
4
Aluminium Methane
carbide
6. (a)
Page 2


1. (b) In Boric acid each B atom is sp
2
 hybridized and contains BO
units which are held together  by hydrogen bonds.
2. (c) AlCl
3
 exists as a dimer (Al
2
Cl
6
). It is a strong Lewis acid as it has
an incomplete octet and has a tendency to gain electrons. AlCl
3
undergoes hydrolysis easily and forms an acidic solution.
AlCl
3
 + 3H
2
O ? Al(OH)
3
 + 3HCl
Option (c) is true that AlCl
3
 sublimes at 180ºC.
3. (c) The IE
1
 of Ga is more than that of Al because of the small atomic
size and greater effective nuclear charge of Ga.
4. (d) Ceramics are inorganic , non-metallic, solid minerals. They come
in a variety of forms, including silicates (silica, SiO
2
 with metal
oxides), oxides (oxygen and metals), carbides (carbon and metals),
aluminates (alumina, Al
2
O
3
 with metal oxides) and nitrides.
The given ceramics are B
4
C (carbides), SiC (carbides), Si
3
N
4
 (nitrides)
and  thus, none of these is an oxide. All of these are non-oxide
ceramics.
5. (b) Because they react with water to form methane gas
Al
4
C
3  
+   12H
2
O –––? 4 Al(OH)
3
 + 3CH
4
Aluminium Methane
carbide
6. (a)
Thus AlCl
3
 cannot be obtained by this method.
7. (c) Fused alumina (Al
2
O
3
) is a bad conductor of electricity. Therefore,
cryolite (Na
3
AlF
6
) and fluorspar (CaF
2
) are added to purified
alumina which not only make alumina a good conductor of
electricity but also reduce the melting point of the mixture to
around 1140 K.
8. (c) Alum furnishes Al
3+
 ions which bring about coagulation of
negatively charged clay particles, bacteria etc.
9. (c) Due to non-availability of vacant d-orbitals, it cannot exceed its
coordination number more than four. Thus carbon never forms
complexes e.g.,  [CCl
6
]
2– 
deos not exist but [SiCl
6
]
2– 
exists.
10. (b)  
(most common and stable)  (Rhombic)
Although transitions of white to grey tin occurs at any temperature
below 15.2°C, it becomes rapid only at–50°C, unless a catalyst is
present. During the conversion of white tin to grey tin (in cold
countries) volume increases. Grey Sn is very brittle easily
crumbles down to powder. This phenomenon is called tin diseases,
tin past or tin plague.
11. (a) 
Soluble complex it is 
insoluble in NH
4
OH
12. (d)
Page 3


1. (b) In Boric acid each B atom is sp
2
 hybridized and contains BO
units which are held together  by hydrogen bonds.
2. (c) AlCl
3
 exists as a dimer (Al
2
Cl
6
). It is a strong Lewis acid as it has
an incomplete octet and has a tendency to gain electrons. AlCl
3
undergoes hydrolysis easily and forms an acidic solution.
AlCl
3
 + 3H
2
O ? Al(OH)
3
 + 3HCl
Option (c) is true that AlCl
3
 sublimes at 180ºC.
3. (c) The IE
1
 of Ga is more than that of Al because of the small atomic
size and greater effective nuclear charge of Ga.
4. (d) Ceramics are inorganic , non-metallic, solid minerals. They come
in a variety of forms, including silicates (silica, SiO
2
 with metal
oxides), oxides (oxygen and metals), carbides (carbon and metals),
aluminates (alumina, Al
2
O
3
 with metal oxides) and nitrides.
The given ceramics are B
4
C (carbides), SiC (carbides), Si
3
N
4
 (nitrides)
and  thus, none of these is an oxide. All of these are non-oxide
ceramics.
5. (b) Because they react with water to form methane gas
Al
4
C
3  
+   12H
2
O –––? 4 Al(OH)
3
 + 3CH
4
Aluminium Methane
carbide
6. (a)
Thus AlCl
3
 cannot be obtained by this method.
7. (c) Fused alumina (Al
2
O
3
) is a bad conductor of electricity. Therefore,
cryolite (Na
3
AlF
6
) and fluorspar (CaF
2
) are added to purified
alumina which not only make alumina a good conductor of
electricity but also reduce the melting point of the mixture to
around 1140 K.
8. (c) Alum furnishes Al
3+
 ions which bring about coagulation of
negatively charged clay particles, bacteria etc.
9. (c) Due to non-availability of vacant d-orbitals, it cannot exceed its
coordination number more than four. Thus carbon never forms
complexes e.g.,  [CCl
6
]
2– 
deos not exist but [SiCl
6
]
2– 
exists.
10. (b)  
(most common and stable)  (Rhombic)
Although transitions of white to grey tin occurs at any temperature
below 15.2°C, it becomes rapid only at–50°C, unless a catalyst is
present. During the conversion of white tin to grey tin (in cold
countries) volume increases. Grey Sn is very brittle easily
crumbles down to powder. This phenomenon is called tin diseases,
tin past or tin plague.
11. (a) 
Soluble complex it is 
insoluble in NH
4
OH
12. (d)
A and B are  and .
13. (c) Hydrolysis of substituted chlorosilanes yield corresponding
silanols which undergo polymerisation.
Polymerisation of dialkyl silandiol yields linear thermoplastic polymer.
 
14. (d) Inertness of ns
2
 electrons of the valence shell to participate in
bonding on moving down the group in heavier p-block elements is
called inert pair effect.
As a result, Pb(II) is more stable than Pb(IV)
Sn(IV) is more stable than Sn(II)
? Pb(IV) is easily reduced to Pb(II) and can acts as an oxidising
agent whereas Sn(II) is easily oxidised to Sn(IV) and can acts as a
reducing agent.
15. (c) CO
2
 forms carbonic acid H
2
CO
3
, when dissolved in water, CO is
neutral, whereas other two GeO
2
 and SnO
2
 are solids.
16. (b) Na
2
B
4
O
7
. 10 H
2
O Na
2
B
4
O
7
Page 4


1. (b) In Boric acid each B atom is sp
2
 hybridized and contains BO
units which are held together  by hydrogen bonds.
2. (c) AlCl
3
 exists as a dimer (Al
2
Cl
6
). It is a strong Lewis acid as it has
an incomplete octet and has a tendency to gain electrons. AlCl
3
undergoes hydrolysis easily and forms an acidic solution.
AlCl
3
 + 3H
2
O ? Al(OH)
3
 + 3HCl
Option (c) is true that AlCl
3
 sublimes at 180ºC.
3. (c) The IE
1
 of Ga is more than that of Al because of the small atomic
size and greater effective nuclear charge of Ga.
4. (d) Ceramics are inorganic , non-metallic, solid minerals. They come
in a variety of forms, including silicates (silica, SiO
2
 with metal
oxides), oxides (oxygen and metals), carbides (carbon and metals),
aluminates (alumina, Al
2
O
3
 with metal oxides) and nitrides.
The given ceramics are B
4
C (carbides), SiC (carbides), Si
3
N
4
 (nitrides)
and  thus, none of these is an oxide. All of these are non-oxide
ceramics.
5. (b) Because they react with water to form methane gas
Al
4
C
3  
+   12H
2
O –––? 4 Al(OH)
3
 + 3CH
4
Aluminium Methane
carbide
6. (a)
Thus AlCl
3
 cannot be obtained by this method.
7. (c) Fused alumina (Al
2
O
3
) is a bad conductor of electricity. Therefore,
cryolite (Na
3
AlF
6
) and fluorspar (CaF
2
) are added to purified
alumina which not only make alumina a good conductor of
electricity but also reduce the melting point of the mixture to
around 1140 K.
8. (c) Alum furnishes Al
3+
 ions which bring about coagulation of
negatively charged clay particles, bacteria etc.
9. (c) Due to non-availability of vacant d-orbitals, it cannot exceed its
coordination number more than four. Thus carbon never forms
complexes e.g.,  [CCl
6
]
2– 
deos not exist but [SiCl
6
]
2– 
exists.
10. (b)  
(most common and stable)  (Rhombic)
Although transitions of white to grey tin occurs at any temperature
below 15.2°C, it becomes rapid only at–50°C, unless a catalyst is
present. During the conversion of white tin to grey tin (in cold
countries) volume increases. Grey Sn is very brittle easily
crumbles down to powder. This phenomenon is called tin diseases,
tin past or tin plague.
11. (a) 
Soluble complex it is 
insoluble in NH
4
OH
12. (d)
A and B are  and .
13. (c) Hydrolysis of substituted chlorosilanes yield corresponding
silanols which undergo polymerisation.
Polymerisation of dialkyl silandiol yields linear thermoplastic polymer.
 
14. (d) Inertness of ns
2
 electrons of the valence shell to participate in
bonding on moving down the group in heavier p-block elements is
called inert pair effect.
As a result, Pb(II) is more stable than Pb(IV)
Sn(IV) is more stable than Sn(II)
? Pb(IV) is easily reduced to Pb(II) and can acts as an oxidising
agent whereas Sn(II) is easily oxidised to Sn(IV) and can acts as a
reducing agent.
15. (c) CO
2
 forms carbonic acid H
2
CO
3
, when dissolved in water, CO is
neutral, whereas other two GeO
2
 and SnO
2
 are solids.
16. (b) Na
2
B
4
O
7
. 10 H
2
O Na
2
B
4
O
7
17. (b)  
18. (b) F and Cl are more oxidising in nature and can achieve Pb in (IV)
O.S. but  can not achieve Pb in (IV) O.S. secondly 
 is strong in oxidising nature and in its presence, 
can not exist.
19. (d) In SiO
2
 (quartz), each of O-atom is shared between two SiO
4
? 4–
tetrahedra.
20. (c) In graphite, carbon is sp
2 
hybridized. Each carbon is thus linked to
three other carbon atoms forming hexagonal rings. Since only
three electrons of each carbon are used in making hexagonal ring,
fourth electron of each carbon is free to move. This makes graphite
a good conductors of heat and electricity.
Further graphite has a two dimensional sheet like structure. These
various sheets are held together by weak van der Waal’s force of
attraction. Due to these weak forces of attraction, one layer can slip
over the other. This makes graphite soft and a good lubricating
agent.
21. (d)  
22. (b) The hydrolysis of Trialkylchlorosilane
R
3
 SiCl yields dimer :
Page 5


1. (b) In Boric acid each B atom is sp
2
 hybridized and contains BO
units which are held together  by hydrogen bonds.
2. (c) AlCl
3
 exists as a dimer (Al
2
Cl
6
). It is a strong Lewis acid as it has
an incomplete octet and has a tendency to gain electrons. AlCl
3
undergoes hydrolysis easily and forms an acidic solution.
AlCl
3
 + 3H
2
O ? Al(OH)
3
 + 3HCl
Option (c) is true that AlCl
3
 sublimes at 180ºC.
3. (c) The IE
1
 of Ga is more than that of Al because of the small atomic
size and greater effective nuclear charge of Ga.
4. (d) Ceramics are inorganic , non-metallic, solid minerals. They come
in a variety of forms, including silicates (silica, SiO
2
 with metal
oxides), oxides (oxygen and metals), carbides (carbon and metals),
aluminates (alumina, Al
2
O
3
 with metal oxides) and nitrides.
The given ceramics are B
4
C (carbides), SiC (carbides), Si
3
N
4
 (nitrides)
and  thus, none of these is an oxide. All of these are non-oxide
ceramics.
5. (b) Because they react with water to form methane gas
Al
4
C
3  
+   12H
2
O –––? 4 Al(OH)
3
 + 3CH
4
Aluminium Methane
carbide
6. (a)
Thus AlCl
3
 cannot be obtained by this method.
7. (c) Fused alumina (Al
2
O
3
) is a bad conductor of electricity. Therefore,
cryolite (Na
3
AlF
6
) and fluorspar (CaF
2
) are added to purified
alumina which not only make alumina a good conductor of
electricity but also reduce the melting point of the mixture to
around 1140 K.
8. (c) Alum furnishes Al
3+
 ions which bring about coagulation of
negatively charged clay particles, bacteria etc.
9. (c) Due to non-availability of vacant d-orbitals, it cannot exceed its
coordination number more than four. Thus carbon never forms
complexes e.g.,  [CCl
6
]
2– 
deos not exist but [SiCl
6
]
2– 
exists.
10. (b)  
(most common and stable)  (Rhombic)
Although transitions of white to grey tin occurs at any temperature
below 15.2°C, it becomes rapid only at–50°C, unless a catalyst is
present. During the conversion of white tin to grey tin (in cold
countries) volume increases. Grey Sn is very brittle easily
crumbles down to powder. This phenomenon is called tin diseases,
tin past or tin plague.
11. (a) 
Soluble complex it is 
insoluble in NH
4
OH
12. (d)
A and B are  and .
13. (c) Hydrolysis of substituted chlorosilanes yield corresponding
silanols which undergo polymerisation.
Polymerisation of dialkyl silandiol yields linear thermoplastic polymer.
 
14. (d) Inertness of ns
2
 electrons of the valence shell to participate in
bonding on moving down the group in heavier p-block elements is
called inert pair effect.
As a result, Pb(II) is more stable than Pb(IV)
Sn(IV) is more stable than Sn(II)
? Pb(IV) is easily reduced to Pb(II) and can acts as an oxidising
agent whereas Sn(II) is easily oxidised to Sn(IV) and can acts as a
reducing agent.
15. (c) CO
2
 forms carbonic acid H
2
CO
3
, when dissolved in water, CO is
neutral, whereas other two GeO
2
 and SnO
2
 are solids.
16. (b) Na
2
B
4
O
7
. 10 H
2
O Na
2
B
4
O
7
17. (b)  
18. (b) F and Cl are more oxidising in nature and can achieve Pb in (IV)
O.S. but  can not achieve Pb in (IV) O.S. secondly 
 is strong in oxidising nature and in its presence, 
can not exist.
19. (d) In SiO
2
 (quartz), each of O-atom is shared between two SiO
4
? 4–
tetrahedra.
20. (c) In graphite, carbon is sp
2 
hybridized. Each carbon is thus linked to
three other carbon atoms forming hexagonal rings. Since only
three electrons of each carbon are used in making hexagonal ring,
fourth electron of each carbon is free to move. This makes graphite
a good conductors of heat and electricity.
Further graphite has a two dimensional sheet like structure. These
various sheets are held together by weak van der Waal’s force of
attraction. Due to these weak forces of attraction, one layer can slip
over the other. This makes graphite soft and a good lubricating
agent.
21. (d)  
22. (b) The hydrolysis of Trialkylchlorosilane
R
3
 SiCl yields dimer :
23. (a) The linking of identical atoms with each other to form long chains
is called catenation. However, this property decreases from carbon
to lead. Decrease of this property is associated with M-M bond
energy which decreases from carbon to lead.
24. (c) The feldspars are most abundant aluminosilicate minerals in the Earth
surface. The silicon atoms and aluminium atoms occupy the centres of
interlinked tetrahedra of  and . These tetrahedra
connect at each corner to other tetrahedra forming an intricate, three
dimesional, negatively charged framework. The sodium cations sit
within the voids in this structure.
25. (c) CO
2
 being more dense covers the igniting material more
effectively than N
2
.