Carbon and its compounds
Carbon
Symbol: C Atomic
number: 6 Atomic mass: 12
Electronic configuration: [He] 2s2 2p4 Valency:
4
Most stable isotope: C12 Group: 16 or IV A
Occurrence:
·
Carbon occurs in the earth in the form of
diamond, graphite coal etc. in free states.
·
In combined states, it is found in the form of
carbonate such as calcium carbonate, magnesium carbonate, dolomite, organic
compounds etc.
Allotropic
form of carbon
Allotropes are the same element that can exist in different
physical forms. E.g., diamond and graphite are two physical forms of carbon and
hence are called allotropes of carbon.
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1. What
is meant by allotropy? Name the latest
discovered form of carbon and give its one use. 2
Hint: nanotubes, nano buds
Diamond:
Ø Purest
form of carbon, a crystalline allotrope of carbon.
Ø Shining
of diamonds is due to the total internal reflection. Its refractive index is
high (2.45).
Ø Extremely
unreactive.
Ø Each
carbon atom is tetrahedrally bonded to four other carbon atoms, with sp3
hybridisation making a bond angle of 109o 24’.
Ø
The hardness, high melting point and high
density (3.5) of a diamond are due to the extension of these strong covalent
bonds to form a giant three-dimensional covalent network as shown in the figure.
Ø
All the valence shell electrons of carbon are
involved in bond formation and there is no free electron. So diamonds are bad
conductor of electricity.
Ø
Though chemically inactive burns in air at 8000C
to give CO2.
C + O2 → CO2
Uses:
·
In jewellery as a gem because it reflects light.
·
For cutting glass and making borer for rock
drilling.
·
For grinding and polishing of hard materials.
2.
Name the hardest allotrope of carbon and mention
its use. 1
Graphite:
Ø Another
crystalline allotrope of carbon.
Ø Out
of 4 valence electrons, only three are involved in the formation of covalent
bond with other carbon atoms. The free electrons make it a good conductor of
electricity.
Ø It
is composed of hexagonal layers of carbon atoms, with two adjacent layers held
with each other by Van der Waal’s force
Ø Due
to the weak Van der Waals force, the two hexagonal layers can slide over each
other. This property of graphite makes its use for lubricant.
Uses:
Ø Lubricants
for machines working at high temperature.
Ø Making
electrodes, as it is good conductor of electricity.
Ø Making
pencil 'lead'
Fullerene:
Ø The
most common form of fullerene is C60
Ø It
is composed of fused system of 5-membered and 6-membered rings
Ø Each
carbon atom is sp2 hybridized and therefore has free electrons. Thus
fullerenes are good conductor of electricity.
or 
Uses
Ø In
biomedical.
Ø Lubricant
for micro machines.
Ø To
make superconductors.
3. What
is meant by fullerene? Mention its use. 2
Graphene:
Ø It
is one of the crystalline allotropes of carbon with the thickness of an atom.
Ø It
is a good conductor of electricity and is about 100 times stronger than steel.
Ø Used
in solar panels and medicines.
Charcoal:
Ø Amorphous
form of carbon and has high surface area.
Ø Depending
upon the source of origin, charcoal may be classified as: plant, animal and
activated charcoal.
Ø Plant
charcoal is obtained from wood, animal charcoal from animal’s blood or bone and
activated charcoal is derived by treating charcoal with high-temperature steam.
Uses
Ø As
a fuel.
Ø Adsorbing
gases and purifying and clarifying liquids.
Ø As
a reductant
Ø As
a gun powder
Ø For
refining oil, sugar etc.
Lamp Black:
Ø It
is obtained by burning natural and other carbon compounds in a limited supply
of air.
Ø Used
to prepare printer ink, shoe polish and black paint.
Gas carbon:
Ø It
is carbon deposited on the interior part of the retort during the manufacture
of coal gas.
Ø It
is a good conductor of electricity.
Coal:
Ø It
is formed by the partial decomposition of vegetable matter in the presence of
moisture at high pressure and temperature.
Ø It
is used as fuel.
Coke:
Ø It
is obtained as a form of residue after the destructive distillation of coal.
Ø It
is used as fuel as well as reducing agent.
4. Write
a short note on the allotropes of carbon. 5
1. The allotrope of carbon used for
making lead pencil is
a.
Lamp black b. Charcoal c.
Graphite d. Gas carbon
2. Fullerene is an allotrope of
a.
C b. P c. S d. F
3. Which of the following is good
conductor of heat and electricity?
a. Coal b. Graphite c. Charcoal d. Coke
4. Diamond has
a. Ionic bond b.
Covalent bond
c. Coordinate bond d.
all of the above
5. Diamond is an example of
a.
covalent
solid c. electrovalent
solid
b.
solid with
hydrogen bond d. glass
6. All tetravalent state of carbon
show
a.
sp hybridization
b.
sp2
hybridization
c.
sp3
hybridization
d.
can show any
of the above hybridization
7. Which of the following shows
electrical conduction?
a.
Diamond b. Graphite c. Charcoal d. Coal
8. Graphite conducts electricity
because of
a.
Weak Van der
Waal's forces between layers
b.
sp2
hybridized C- atom in each layer
c.
covalent
bonds between C-atoms of layers
d.
delocalized electron in each layer
9. Carbon in graphite is ……………
hybridized.
a.
sp b. sp2 c. sp3 d. none
10. Percentage of lead in carbon is
a.
0% b. 75% c. 80% d.
85%
Properties
of Carbon Monoxide
Carbon monoxide is highly poisonous gas. It has about twenty
times more affinity towards haemoglobin than oxygen. Carbon monoxide combines
with haemoglobin to form carboxyhaemoglobin, which is relatively more stable
complex. Therefore, it cannot combine with more oxygen. Consequently, the
oxygen content of the blood is reduced, which causes suffocation and death.
5.
Why CO harmful gas? 2
Reducing action:
Carbon monoxide acts as a reducing agent.
Ø
It is used to reduce metallic oxide to metal in
metallurgical processes.
ZnO + CO ® Zn + CO2
Fe2O3 + CO ® Fe +
CO2 (at 600-9000C)
PbO + CO ® Pb + CO2
Ø
Carbon monoxide can reduce iodine oxide to
iodine
I2O5 + CO ® I2
+ CO2
Ø
Carbon monoxide reduces Tollen’s reagent to
metallic silver. Ammoniacal silver nitrate solution is Tollen’s reagent. Its
molecular form is [Ag(NH3)2]OH.
[Ag(NH3)2]OH
+ CO ®
Ag + NH3 + CO2 +
H2O
Silver mirror
Ø
CO reduces Fehling’s solution to produce red precipitate of cuprous oxide. Fehling solution is basic copper sulphate in
presence of sodium potassium tartarate.
CuSO4 +
NaOH ®
Cu(OH)2 + Na2SO4
Cu(OH)2 + CO ® Cu2O
+ H2O + CO2
6. Write
a chemical reaction to show the reducing action of CO. 1
7. What
happens when the CO gas is passed through heated ferric oxide? 2
Reaction with metals:
Formation of carbonyl compound:
Carbon monoxide when passed through some metals like nickel,
iron, cobalt, it forms carbonyl compounds.
E.g., when carbon monoxide is passed into finely divided
nickel at about 80oC, nickel tetra carbonyl is formed, which on
further heating to 180oC decomposes into metallic nickel.
Ni + CO ® Ni(CO)4
Ni(CO)4 ® Ni +
CO
This is used for the purification of nickel.
Action with Non metals
Action with hydrogen:
When a mixture of carbon monoxide gas and hydrogen gas is passed into the
mixture of ZnO and Cr2O3 catalyst at 300oC and
200 atmospheric pressure, methyl alcohol is produced.
CO
+ H2 ®
CH3OH
Action with Cl2:
Carbon monoxide reacts with chlorine in the presence of sunlight to produce
poisonous phosgene gas.
CO + Cl2 ® COCl2
(Phosgene
gas)
Action with sulphur: When
CO is heated with sulphur, carbonyl sulphide is formed.
CO + S ® COS
(carbonyl sulphide)
8. What
products would you expect when CO is heated with H2 in presence of
ZnO and Cr2O3? 1
9. What
happens when carbon monoxide is treated with Cl2 in presence of
sunlight? 1
10. How would
you convert CO into CO2 and vice versa? 2
Hint: 2 CO + O2 ® 2 CO2;
CO2 + C ® 2 CO
Most
of the above reactions are not balanced. Please practice balancing equations.
Uses of carbon monoxide:
·
As reducing agent in metallurgical processes.
·
To prepare carbonyl compounds which are used in
organic synthesis.
·
In the purification of metals like nickel, iron
etc.
·
As fuel in combination with hydrogen and
nitrogen. E.g. Water gas (CO+H2) and producer gas (CO+N2).
·
Misused in warfare to prepare phosgene gas.
11. Why is
carbon used as the most common reducing agent in thermal metallurgy? 2
Hint: 1. Since it is in powder form, it can increase the rate of
the reaction.
2. It is oxidized to carbon
monoxide, which is also a good reducing agent
3. The conversion of carbon to
carbon monoxide is exothermic process. So heat energy produced helps in
metallurgy.
11. The gas that combines with
haemoglobin to damage its oxygen carrying capacity is
a.
CO2 b.
CO c. N2 d. H2
12. Carbon monoxide reduces Fehling's
solution into
a.
Cu(OH)2 b. CuO c.
CuSO4 d. Cu2O
13. CO reacts with Cl2 in
presence of sunlight to give
a.
COCl2 b. CaOCl2 c. CO2 d. CuCOCl
14. Which of the following statements
is not true?
a.
Diamond is
the 100% pure form of carbon.
b.
Coke is used
as an oxidizing agent in metallurgy
c.
Fullerenes
are the new allotropic forms of carbon.
15. CO is an
a.
Acidic oxide c. Basic oxide
b.
Neutral
oxide d. Amphoteric
oxide
16. Water gas is a mixture of
a.
CO2
and H2O c. CO and H2O
b.
CO, N2
and H2 d. CO and H2
*** This is not a complete note. It is just to guide
you. It is recommended to study prescribed textbooks along with this material.
***
Symbol: C Atomic
number: 6 Atomic mass: 12
Electronic configuration: [He] 2s2 2p4 Valency:
4
Most stable isotope: C12 Group: 16 or IV A
Occurrence:
·
Carbon occurs in the earth in the form of
diamond, graphite coal etc. in free states.
·
In combined states, it is found in the form of
carbonate such as calcium carbonate, magnesium carbonate, dolomite, organic
compounds etc.
Allotropic
form of carbon
Allotropes are the same element that can exist in different
physical forms. E.g., diamond and graphite are two physical forms of carbon and
hence are called allotropes of carbon.
|
|
|||||
|
|||||
|
|||||
1. What
is meant by allotropy? Name the latest
discovered form of carbon and give its one use. 2
Hint: nanotubes, nano buds
Diamond:
Ø Purest
form of carbon, a crystalline allotrope of carbon.
Ø Shining
of diamonds is due to the total internal reflection. Its refractive index is
high (2.45).
Ø Extremely
unreactive.
Ø Each
carbon atom is tetrahedrally bonded to four other carbon atoms, with sp3
hybridisation making a bond angle of 109o 24’.
Ø
The hardness, high melting point and high
density (3.5) of a diamond are due to the extension of these strong covalent
bonds to form a giant three-dimensional covalent network as shown in the figure.
Ø
All the valence shell electrons of carbon are
involved in bond formation and there is no free electron. So diamonds are bad
conductor of electricity.
Ø
Though chemically inactive burns in air at 8000C
to give CO2.
C + O2 → CO2
Uses:
·
In jewellery as a gem because it reflects light.
·
For cutting glass and making borer for rock
drilling.
·
For grinding and polishing of hard materials.
2.
Name the hardest allotrope of carbon and mention
its use. 1
Graphite:
Ø Another
crystalline allotrope of carbon.
Ø Out
of 4 valence electrons, only three are involved in the formation of covalent
bond with other carbon atoms. The free electrons make it a good conductor of
electricity.
Ø It
is composed of hexagonal layers of carbon atoms, with two adjacent layers held
with each other by Van der Waal’s force
Ø Due
to the weak Van der Waals force, the two hexagonal layers can slide over each
other. This property of graphite makes its use for lubricant.
Uses:
Ø Lubricants
for machines working at high temperature.
Ø Making
electrodes, as it is good conductor of electricity.
Ø Making
pencil 'lead'
Fullerene:
Ø The
most common form of fullerene is C60
Ø It
is composed of fused system of 5-membered and 6-membered rings
Ø Each
carbon atom is sp2 hybridized and therefore has free electrons. Thus
fullerenes are good conductor of electricity.
or
Uses
Ø In
biomedical.
Ø Lubricant
for micro machines.
Ø To
make superconductors.
3. What
is meant by fullerene? Mention its use. 2
Graphene:
Ø It
is one of the crystalline allotropes of carbon with the thickness of an atom.
Ø It
is a good conductor of electricity and is about 100 times stronger than steel.
Ø Used
in solar panels and medicines.
Charcoal:
Ø Amorphous
form of carbon and has high surface area.
Ø Depending
upon the source of origin, charcoal may be classified as: plant, animal and
activated charcoal.
Ø Plant
charcoal is obtained from wood, animal charcoal from animal’s blood or bone and
activated charcoal is derived by treating charcoal with high temperature steam.
Uses
Ø As
a fuel.
Ø Adsorbing
gases and purifying and clarifying liquids.
Ø As
a reductant
Ø As
a gun powder
Ø For
refining oil, sugar etc.
Lamp Black:
Ø It
is obtained by burning natural and other carbon compounds in a limited supply
of air.
Ø Used
to prepare printer ink, shoe polish and black paint.
Gas carbon:
Ø It
is carbon deposited on the interior part of the retort during the manufacture
of coal gas.
Ø It
is a good conductor of electricity.
Coal:
Ø It
is formed by the partial decomposition of vegetable matter in the presence of
moisture at high pressure and temperature.
Ø It
is used as fuel.
Coke:
Ø It
is obtained as a form of residue after the destructive distillation of coal.
Ø It
is used as fuel as well as reducing agent.
4. Write
a short note on the allotropes of carbon. 5
1. The allotrope of carbon used for
making lead pencil is
a.
Lamp black b. Charcoal c.
Graphite d. Gas carbon
2. Fullerene is an allotrope of
a.
C b. P c. S d. F
3. Which of the following is good
conductor of heat and electricity?
a. Coal b. Graphite c. Charcoal d. Coke
4. Diamond has
a. Ionic bond b.
Covalent bond
c. Coordinate bond d.
all of the above
5. Diamond is an example of
a.
covalent
solid c. electrovalent
solid
b.
solid with
hydrogen bond d. glass
6. All tetravalent state of carbon
show
a.
sp hybridization
b.
sp2
hybridization
c.
sp3
hybridization
d.
can show any
of the above hybridization
7. Which of the following shows
electrical conduction?
a.
Diamond b. Graphite c. Charcoal d. Coal
8. Graphite conducts electricity
because of
a.
Weak Van der
Waal's forces between layers
b.
sp2
hybridized C- atom in each layer
c.
covalent
bonds between C-atoms of layers
d.
delocalized electron in each layer
9. Carbon in graphite is ……………
hybridized.
a.
sp b. sp2 c. sp3 d. none
10. Percentage of lead in carbon is
a.
0% b. 75% c. 80% d.
85%
Properties
of Carbon Monoxide
Carbon monoxide is highly poisonous gas. It has about twenty
times more affinity towards haemoglobin than oxygen. Carbon monoxide combines
with haemoglobin to form carboxyhaemoglobin, which is relatively more stable
complex. Therefore, it cannot combine with more oxygen. Consequently, the
oxygen content of the blood is reduced, which causes suffocation and death.
5.
Why CO harmful gas? 2
Reducing action:
Carbon monoxide acts as a reducing agent.
Ø
It is used to reduce metallic oxide to metal in
metallurgical processes.
ZnO + CO ® Zn + CO2
Fe2O3 + CO ® Fe +
CO2 (at 600-9000C)
PbO + CO ® Pb + CO2
Ø
Carbon monoxide can reduce iodine oxide to
iodine
I2O5 + CO ® I2
+ CO2
Ø
Carbon monoxide reduces Tollen’s reagent to
metallic silver. Ammoniacal silver nitrate solution is Tollen’s reagent. Its
molecular form is [Ag(NH3)2]OH.
[Ag(NH3)2]OH
+ CO ®
Ag + NH3 + CO2 +
H2O
Silver mirror
Ø
CO reduces Fehling’s solution to produce red precipitate of cuprous oxide. Fehling solution is basic copper sulphate in
presence of sodium potassium tartarate.
CuSO4 +
NaOH ®
Cu(OH)2 + Na2SO4
Cu(OH)2 + CO ® Cu2O
+ H2O + CO2
6. Write
a chemical reaction to show the reducing action of CO. 1
7. What
happens when the CO gas is passed through heated ferric oxide? 2
Reaction with metals:
Formation of carbonyl compound:
Carbon monoxide when passed through some metals like nickel,
iron, cobalt, it forms carbonyl compounds.
E.g., when carbon monoxide is passed into finely divided
nickel at about 80oC, nickel tetra carbonyl is formed, which on
further heating to 180oC decomposes into metallic nickel.
Ni + CO ® Ni(CO)4
Ni(CO)4 ® Ni +
CO
This is used for the purification of nickel.
Action with Non metals
Action with hydrogen:
When a mixture of carbon monoxide gas and hydrogen gas is passed into the
mixture of ZnO and Cr2O3 catalyst at 300oC and
200 atmospheric pressure, methyl alcohol is produced.
CO
+ H2 ®
CH3OH
Action with Cl2:
Carbon monoxide reacts with chlorine in the presence of sunlight to produce
poisonous phosgene gas.
CO + Cl2 ® COCl2
(Phosgene
gas)
Action with sulphur: When
CO is heated with sulphur, carbonyl sulphide is formed.
CO + S ® COS
(carbonyl sulphide)
8. What
products would you expect when CO is heated with H2 in presence of
ZnO and Cr2O3? 1
9. What
happens when carbon monoxide is treated with Cl2 in presence of
sunlight? 1
10. How would
you convert CO into CO2 and vice versa? 2
Hint: 2 CO + O2 ® 2 CO2;
CO2 + C ® 2 CO
Most
of the above reactions are not balanced. Please practice balancing equations.
Uses of carbon monoxide:
·
As reducing agent in metallurgical processes.
·
To prepare carbonyl compounds which are used in
organic synthesis.
·
In the purification of metals like nickel, iron
etc.
·
As fuel in combination with hydrogen and
nitrogen. E.g. Water gas (CO+H2) and producer gas (CO+N2).
·
Misused in warfare to prepare phosgene gas.
11. Why is
carbon used as the most common reducing agent in thermal metallurgy? 2
Hint: 1. Since it is in powder form, it can increase the rate of
the reaction.
2. It is oxidized to carbon
monoxide, which is also a good reducing agent
3. The conversion of carbon to
carbon monoxide is exothermic process. So heat energy produced helps in
metallurgy.
11. The gas that combines with
haemoglobin to damage its oxygen carrying capacity is
a.
CO2 b.
CO c. N2 d. H2
12. Carbon monoxide reduces Fehling's
solution into
a.
Cu(OH)2 b. CuO c.
CuSO4 d. Cu2O
13. CO reacts with Cl2 in
presence of sunlight to give
a.
COCl2 b. CaOCl2 c. CO2 d. CuCOCl
14. Which of the following statements
is not true?
a.
Diamond is
the 100% pure form of carbon.
b.
Coke is used
as an oxidizing agent in metallurgy
c.
Fullerenes
are the new allotropic forms of carbon.
15. CO is an
a.
Acidic oxide c. Basic oxide
b.
Neutral
oxide d. Amphoteric
oxide
16. Water gas is a mixture of
a.
CO2
and H2O c. CO and H2O
b.
CO, N2
and H2 d. CO and H2
*** This is not a complete note. It is just to guide
you. It is recommended to study prescribed textbooks along with this material.
***
Labels: Carbonmonoxide, Chemistry class 11 NEB, chemistry notes, concise and comprehensive, diamond, fullerene, graphide, Inorganic chemistry, nano chemistry, nonmetals
posted by Subarnam Oli @ March 23, 2023
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