Bond Energy Calculator – Easily Calculate Bond Enthalpy
Bond Energy Calculator
Welcome to our handy bond energy calculator that determines the energy required to break or form chemical bonds between atoms.
When calculating the bond energy of H₂O, it considers the O-H bonds: if breaking one O-H bond requires 463 kJ/mol, then breaking both O-H bonds in water requires 926 kJ/mol.
Bond Energy Chart
| Bond Type | Bond Energy (kJ/mol) | Bond Energy (kcal/mol) |
|---|---|---|
| H–H (Hydrogen) | 436 | 104 |
| C–H (Carbon-Hydrogen) | 412 | 98 |
| C–C (Carbon-Carbon) | 348 | 83 |
| C=C (Carbon=Carbon) | 614 | 147 |
| C≡C (Carbon≡Carbon) | 839 | 201 |
| O–H (Oxygen-Hydrogen) | 463 | 111 |
| O=O (Oxygen=Oxygen) | 498 | 119 |
| N–H (Nitrogen-Hydrogen) | 391 | 93 |
| N≡N (Nitrogen≡Nitrogen) | 942 | 225 |
| F–F (Fluorine-Fluorine) | 158 | 38 |
| Cl–Cl (Chlorine-Chlorine) | 243 | 58 |
| Br–Br (Bromine-Bromine) | 193 | 46 |
| I–I (Iodine-Iodine) | 151 | 36 |
Bond Energy Calculation Formula
The equation for calculating total bond energy is:
ΔH = Σ(Bonds Broken) - Σ(Bonds Formed)- Positive ΔH: Endothermic reaction (energy absorbed).
- Negative ΔH: Exothermic reaction (energy released).
Calculating ethane (C₂H₆):
- One C-C bond: 1 × 348 kJ/mol
- Six C-H bonds: 6 × 413 kJ/mol
- Total bond energy = 348 + (6 × 413) = 2826 kJ/mol
How to Calculate Bonding Energy?
To calculate bonding energy, identify all bonds in the molecule and multiply each bond’s energy by its frequency. Consider propane (C₃H₈):
- Identify bonds: Two C-C bonds, eight C-H bonds
- Multiply: (2 × 348) + (8 × 413) = 3800 kJ/mol
- Sum all values for total bond energy
Methane (CH₄) bond energy calculation:
Breaking all C-H bonds = 4 × 413 kJ/mol = 1652 kJ/mol
Carbon Dioxide (CO₂) total bond energy:
Breaking two C=O bonds = 2 × 799 kJ/mol = 1598 kJ/mol
Ethanol (C₂H₅OH) complete breakdown:
Breaking C-C bond = 348 kJ/mol
Breaking C-H bonds = 5 × 413 kJ/mol
Breaking C-O bond = 360 kJ/mol
Breaking O-H bond = 463 kJ/mol
Total = 3286 kJ/mol
Nitrogen (N₂) triple bond:
Breaking N≡N bond = 941 kJ/mol
Ammonia (NH₃) bond energy:
Breaking N-H bonds = 3 × 391 kJ/mol = 1173 kJ/mol
What is the Bond Energy of HCl?
The H-Cl bond energy is 431 kJ/mol, meaning it requires this much energy to break one mole of H-Cl bonds. When HCl forms from H₂ and Cl₂:
Break H-H bond: 436 kJ/mol
Break Cl-Cl bond: 242 kJ/mol
Form two H-Cl bonds: -2(431) kJ/mol
Net energy change = 436 + 242 – 862 = -184 kJ/mol
What is Bond Energy?
Bond energy represents the energy required to break one mole of bonds in gaseous molecules. It’s crucial for understanding molecular stability and chemical reactivity. Higher bond energy indicates stronger bonds, like the N≡N triple bond (941 kJ/mol) compared to the N-N single bond (160 kJ/mol). Bond energies help predict reaction energetics and molecular stability in chemical processes.