Bond Strength - Bond Energy & Bond-dissociation Energy, Factors Affecting Bond Strength (2024)

What is Bond Strength?

The strength of a bond shows how tightly each atom is bound to another, and how much energy is necessary to break the binding between the two atoms.

Bond strength is defined as the strength with which a chemical bond holds two atoms together in chemistry. This is usually expressed in terms of the amount of energy required to break the bond in kilocalories per mole.

Table of Contents

• Bond Energy
• Bond-dissociation Energy
• Factors Affecting Bond Strength
• Difference between Bond Dissociation Energy Versus Bond Energy
• Frequently Asked Questions – FAQs

Bond Energy

The amount of energy produced when one mole of bonds is generated from isolated atoms in the gaseous state, or the amount of energy necessary to dissolve one mole of bonds present between the atoms in gaseous molecules, is referred to as bond energy. Bond dissociation energy is commonly referred to as bond energy.

Read more:Bond Energy

It’s important to remember that the bond energy of a chemical bond in a compound is the average of all of the chemical bonds’ individual bond dissociation enthalpies.

Bond-dissociation Energy

The amount of energy necessary to hom*olytically fracture a chemical bond is known as bond dissociation energy. The energy required to break a chemical bond is known as bond dissociation energy. It’s a way to measure the strength of a chemical bond.

Only diatomic compounds have bond dissociation energy equal to bond energy. The Si-F bond has the highest bond dissociation energy. A covalent bond has the weakest energy, which is comparable to the strength of intermolecular forces.

Read more: Bond-dissociation Energy

Factors Affecting Bond Strength

The amount of energy necessary to break one mole of a specific type of bond and separate it into gaseous atoms is known as bond energy. The bond energy is directly related to the strength of a chemical bond.

The following are the factors that affect the bond strength.

1. The bond length increases as the atom’s size increases, and the bond dissociation energy decreases, resulting in a decrease in bond strength.
2. The bond dissociation energy of a bond between two identical atoms increases as the bond multiplicity increases.
3. The larger the number of lone pairs of electrons on linked atoms, the greater the repulsion between them, and thus the lower the bond dissociation energy.
4. As the hybrid orbitals’ orbital contribution grows, the bond energy increases. As a result, bond energy drops in the order sp sp2 sp3.
5. The higher the electronegativity difference, the higher the bond polarity and thus the bond strength.

Difference between Bond Dissociation Energy Versus Bond Energy

For diatomic compounds, bond dissociation energy is equal to bond energy. This is due to the fact that bond dissociation energy is the energy of a single chemical bond, whereas bond energy is the average value of all bond dissociation energies of all bonds of a particular type inside a molecule.

Consider removing hydrogen atoms from a methane molecule one at a time. The energy of the first bond dissociation is 105 kcal/mol, the second is 110 kcal/mol, the third is 101 kcal/mol, and the fourth is 81 kcal/mol. The bond energy, or 99 kcal/mol, is the average of the bond dissociation energies. For any of the C-H bonds in the methane molecule, the bond energy does not equal the bond dissociation energy.