l Potential Energy and Covalent Bonds
è Potential energy in molecules is stored in the form of chemical bond energy
è Enthalpy DHo is a measure of the change in bond energies in a reaction
è Exothermic reactions
H DHo is negative and heat is evolved
H Potential energy in the bonds of reactants is more than that of products
è Endothermic reactions
H DHo is positive and heat is absorbed
H Potential energy in the bonds of reactants is less than that of products
Problem:
How the relationship between potential energy and covalent bonds?
The solution:
So far, a simple description of covalent bond is a pair of points which are divided between two atoms. Directional nature of covalent bonds have a very strong and has a particular shape that is usually fixed shape even though the substance had experienced physical changes, such as strength or melt.
There are two approaches is important to know how the formation of chemical bonds based on quantum mechanics. One such approach is called the valence bond theory, which allows us to keep using an atomic picture of what we know to form a covalent bond.
1. Valence bond theory is defined as follows: When two atoms form a covalent bond, one of the atomic orbitals overlap (overlap) with other atomic orbitals.
2. Two of the spinning electron pairs can be divided between the two overlapping orbitals, electron density is concentrated between the nucleus of atoms that form a bond.
3. Covalent bond strength, measured in terms of energy when broken down, in proportion to the amount of orbital overlap, the overlapping degree of increase in size, growing stronger ties and increased slightly the potential energy of atoms, when a bond is formed. As a result tend to be in a position to form atomic orbitals overlap in the maximum amount.
There are two approaches is important to know how the formation of chemical bonds based on quantum mechanics. One such approach is called the valence bond theory, which allows us to keep using an atomic picture of what we know to form a covalent bond.
1. Valence bond theory is defined as follows: When two atoms form a covalent bond, one of the atomic orbitals overlap (overlap) with other atomic orbitals.
2. Two of the spinning electron pairs can be divided between the two overlapping orbitals, electron density is concentrated between the nucleus of atoms that form a bond.
3. Covalent bond strength, measured in terms of energy when broken down, in proportion to the amount of orbital overlap, the overlapping degree of increase in size, growing stronger ties and increased slightly the potential energy of atoms, when a bond is formed. As a result tend to be in a position to form atomic orbitals overlap in the maximum amount.
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