Concept:Bond energy (or bond enthalpy) measures the strength of a chemical bond. It is quantified as the energy required to break one mole of a specific bond type in the gas phase.
Formula:$$ \text{Standard SI Unit for Molar Enthalpy} = \text{kJ/mol} $$
Solution:- Because individual atoms are incredibly small, chemists measure bond energies on a macroscopic scale using moles.
- The energy is typically very large, so it is expressed in kilojoules (kJ) rather than standard Joules.
- Therefore, the standard unit is Kilojoules per mole (kJ/mol).
Why other options are incorrect:- Option B & Option C: While calories and Joules are units of energy, they lack the per-mole (macroscopic) scaling standard in chemical thermodynamics.
- Option D: Volt is a unit of electrical potential, not chemical energy.
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