Question

How much energy does it take to break a hydrogen bond?

Answer 1

Hydrogen Bond: It is an electrostatic attraction between a hydrogen atom that is bonded to a more electronegative atom such as Nitrogen, Oxygen.

• Hydrogen bonds are weak relative to covalent bonds.
• The amount of energy required to break a hydrogen bond is about 111 Kcal/mole or in more proper SI units, 464 kJ/mole or less than 5% of the energy of a “real” Covalent band.
• For example, in order to break the hydrogen bonds in one mole of water without changing the phase of the substance (that is, not causing vaporization), the energy required would be approximately 6.3 kilojoules.
• Therefore, the energy required to break the hydrogen bonds in water can be approximated to 6.3 kilojoules per mole.