Carbon and its compounds
• Carbon compounds are present everywhere i.e in the food that we eat, the
clothes that we wear and even in the pencils we write with. The atomic number
of carbon is 6 and the atomic mass is 12.01g mol-1. Carbon is a member of the
14th group.
• Organic Compounds- Those compounds which consist of carbon essentially and
hydrogen mostly along with other elements like oxygen, sulphur, nitrogen,
halogen etc are called organic compounds.
• The branch of chemistry which deals with the study of these compounds is
called organic chemistry.
Bonding in carbon- “The covalent bond”
• Most carbon compounds are poor conductors of electricity. The boiling point and
melting point of the carbon compounds are low. Forces of attraction between
these molecules of organic compounds are not very strong. As these compounds
are largely non compounds does not give rise to any ions.
• The reactivity of elements if explained as their tendency to attain a completely
filled outer shells, that is attain noble gas configuration. Elements forming ionic
compounds achieve this by either gaining or losing electrons from the outermost
shell.
• In case of carbon, it has four electrons in its outermost shell and needs to gain
or lose four electrons to attain stability. But both gain or lose four electrons is
not feasible for carbon because-
I. After gaining four electrons it will form C4- anion. This anion is unstable as it is
not possible for 6 protons to hold on to 10 electrons. (i.e 4 extra electrons)
II. After losing four electrons it will form C4+ cation. But this is not possible as it
requires huge amount of energy to remove 4 electrons leaving behind an ion
which has six protons holding on to just two electrons.
• Carbon overcomes this problem by sharing its valence electrons with other
atoms of carbon or with atoms of other elements. Not just carbon, but many
other elements form molecules by sharing electrons in this manner. This shared
electrons ‘belong’ to the outermost shells of both the atoms and lead to both
atoms attaining the noble gas configuration.
• Let us see few examples of covalent compounds-
i. Hydrogen molecule(H2)
, The atomic number of hydrogen is 1. Hence hydrogen has one electron in its K-
shell and it requires one more electron to fill the K-shell. So two hydrogen
atoms share their electrons to form a molecule of hydrogen. This completes the
duplet of hydrogen atoms and it gains stability.
The shared pair of electrons is said to constitute a single covalent bond
between the two hydrogen atoms.
A single covalent bond is also represented by a line between the two atoms.
ii. Formation of water molecule (H2O)
Each hydrogen atoms has only one electron in its outermost shell. Therefore,
each hydrogen atoms needs one more electron to achieve the noble gas
configuration of helium. Oxygen has 6 electrons in outermost shell and requires
2 electron to attain the stability or to complete its octet.
iii. Formation of water molecule (H2O)
, iv. Formation of methane molecule (CH4)
Carbon has its atomic number 6 with the electronic configuration of 2,4. It has
4 valence electrons and requires 4 more electrons to complete its octet.
Hydrogen atom has one electron; needs one more electron to get stable
electronic configuration. Therefore, one atom of carbon shares four electrons
with four atoms hydrogen to form four covalent bonds.
• Different kinds of covalent bonds-
➢ Electron pair shared between two atoms results in the formation of a covalent
bond. The shared pair of electrons are called bonding pair of electrons.
➢ If two atoms share one electron pair, bond is known as single covalent bond and
is represented by one dash (-). Ex- H-H for hydrogen molecule.
➢ If two atoms share two electron pair, bond is known as double covalent bond and
is represented by double dash. Ex- O=O for oxygen molecule.
v. Formation of double bond in oxygen (O2) –
Each oxygen atom has 6 electrons in the valence shell. It requires two electrons
to acquire nearest noble gas configuration. Therefore, both the atoms
contribute two electrons each for sharing to form oxygen molecule. In the
molecule, two electron pairs are shared and hence there is a double bond
between the oxygen atoms.
vi. Formation of triple bond in nitrogen (N2) –
• Carbon compounds are present everywhere i.e in the food that we eat, the
clothes that we wear and even in the pencils we write with. The atomic number
of carbon is 6 and the atomic mass is 12.01g mol-1. Carbon is a member of the
14th group.
• Organic Compounds- Those compounds which consist of carbon essentially and
hydrogen mostly along with other elements like oxygen, sulphur, nitrogen,
halogen etc are called organic compounds.
• The branch of chemistry which deals with the study of these compounds is
called organic chemistry.
Bonding in carbon- “The covalent bond”
• Most carbon compounds are poor conductors of electricity. The boiling point and
melting point of the carbon compounds are low. Forces of attraction between
these molecules of organic compounds are not very strong. As these compounds
are largely non compounds does not give rise to any ions.
• The reactivity of elements if explained as their tendency to attain a completely
filled outer shells, that is attain noble gas configuration. Elements forming ionic
compounds achieve this by either gaining or losing electrons from the outermost
shell.
• In case of carbon, it has four electrons in its outermost shell and needs to gain
or lose four electrons to attain stability. But both gain or lose four electrons is
not feasible for carbon because-
I. After gaining four electrons it will form C4- anion. This anion is unstable as it is
not possible for 6 protons to hold on to 10 electrons. (i.e 4 extra electrons)
II. After losing four electrons it will form C4+ cation. But this is not possible as it
requires huge amount of energy to remove 4 electrons leaving behind an ion
which has six protons holding on to just two electrons.
• Carbon overcomes this problem by sharing its valence electrons with other
atoms of carbon or with atoms of other elements. Not just carbon, but many
other elements form molecules by sharing electrons in this manner. This shared
electrons ‘belong’ to the outermost shells of both the atoms and lead to both
atoms attaining the noble gas configuration.
• Let us see few examples of covalent compounds-
i. Hydrogen molecule(H2)
, The atomic number of hydrogen is 1. Hence hydrogen has one electron in its K-
shell and it requires one more electron to fill the K-shell. So two hydrogen
atoms share their electrons to form a molecule of hydrogen. This completes the
duplet of hydrogen atoms and it gains stability.
The shared pair of electrons is said to constitute a single covalent bond
between the two hydrogen atoms.
A single covalent bond is also represented by a line between the two atoms.
ii. Formation of water molecule (H2O)
Each hydrogen atoms has only one electron in its outermost shell. Therefore,
each hydrogen atoms needs one more electron to achieve the noble gas
configuration of helium. Oxygen has 6 electrons in outermost shell and requires
2 electron to attain the stability or to complete its octet.
iii. Formation of water molecule (H2O)
, iv. Formation of methane molecule (CH4)
Carbon has its atomic number 6 with the electronic configuration of 2,4. It has
4 valence electrons and requires 4 more electrons to complete its octet.
Hydrogen atom has one electron; needs one more electron to get stable
electronic configuration. Therefore, one atom of carbon shares four electrons
with four atoms hydrogen to form four covalent bonds.
• Different kinds of covalent bonds-
➢ Electron pair shared between two atoms results in the formation of a covalent
bond. The shared pair of electrons are called bonding pair of electrons.
➢ If two atoms share one electron pair, bond is known as single covalent bond and
is represented by one dash (-). Ex- H-H for hydrogen molecule.
➢ If two atoms share two electron pair, bond is known as double covalent bond and
is represented by double dash. Ex- O=O for oxygen molecule.
v. Formation of double bond in oxygen (O2) –
Each oxygen atom has 6 electrons in the valence shell. It requires two electrons
to acquire nearest noble gas configuration. Therefore, both the atoms
contribute two electrons each for sharing to form oxygen molecule. In the
molecule, two electron pairs are shared and hence there is a double bond
between the oxygen atoms.
vi. Formation of triple bond in nitrogen (N2) –
