Basics of Chemical Bonding

Basics of Chemical Bonding

Definition: it is an attractive force that holds together the atoms and ions etc.

There are three types of chemical bonding

• Electrovalent Bonding
• Covalent Bonding
• Co-ordinate Bonding

Electrovalent or Ionic Bonding

The bond formed by the complete transfer of one or more electrons from the outermost shell of one atom to the outermost shell of another atom is known as ionic or electrovalent bond and the concept is known as electrovalent or ionic bonding.

Properties of Electrovalent or Ionic Compounds

• Electrovalent or ionic bonds are the strongest bonds.
• Electrovalent bonds have high melting and boiling point.
• Electrovalent bonds have a charge separation.
• Electrovalent compounds are non-volatile.
• Electrovalent compounds in solid-state do not conduct heat and electricity but in the molten state, they conduct heat and electricity.
• Electrovalent compounds are soluble in water.
• Electrovalent compounds are insoluble in the organic solvent.
• Electrovalent compounds undergo high-speed ionic reactions.
• Electrovalent compounds undergo electrolytic dissociation.

Covalent Bonding

Definition: Bonds formed by the sharing of electrons are called covalent bond and the concept is known as covalent bonding.

Types of Covalent Compounds

• Polar covalent compounds
• Non-polar covalent compounds

Difference between Polar and Non-Polar Covalent Compounds

Polar covalent compounds	Non-polar covalent compounds
1. Equally distributed between two atoms	1. Unequally distributed between two atoms
2. No charge separation takes place	2. Charge separation takes place
3. Example: H2, cl2, O2, N2, ch4, ccl4	3. Example: H2O, NH3, HCL

 

Properties of Covalent Compounds

• Covalent compounds exist in the gaseous and liquid state
• Their constituent unit is molecules.
• Covalent compounds are volatile compounds.
• Covalent compounds have low melting and boiling point.
• Covalent compounds are bad conductors of heat.
• Covalent compounds are bad conductors of electricity in both solid and liquid states.
• Covalent compounds cannot be electrolyzed in a normal state.
• Covalent compounds are soluble in organic solvents.
• Covalent compounds are insoluble in water.
• Covalent compounds undergo slow speed molecular reactions.
• Covalent compounds undergo isomerization.

Co-ordinate Bonding or Dative Bonding

Definition: Bond formed by both sharing and transfer of electrons is called coordinate bonds and the concept is known as coordinate or dative bonding.

Characteristics of Co-ordinate Bond

• Melting and boiling points are higher than covalent compounds and lower than ionic compounds.
• They are sparingly soluble in a polar solvent.
• They are readily soluble in a non-polar solvent.
• They are bad conductors of heat and electricity.
• The bonds are rigid and directional.
• They show isomerization.
• Example NH4+, N2O3, N2o4, no3-, SO2, H2So4.