Hydrogen Bonding
Chemical Bonding of Class 11
An atom of hydrogen linked covalently to a strongly electronegative atom can establish an extra weak attachment to another electronegative atom in the same or different molecules. This attachment is called a hydrogen bond. To distinguish from a normal covalent bond, a hydrogen bond is represented by a broken line eg X – H…Y where X & Y are two electronagative atoms. The strength of hydrogen bond is quite low about 2-10 kcal mol–1 or 8.4–42 kJ mol–1 as compared to a covalent bond strength 50–100 kcal mol–1 or 209 –419 kJ mol–1
Conditions for Hydrogen Bonding:
- Hydrogen should be linked to a highly electronegative element.
- The size of the electronegative element must be small.
These two criteria are fulfilled by F, O, and N in the periodic table. Greater the electronegativity and smaller the size, the stronger is the hydrogen bond which is evident from the relative order of energies of hydrogen bonds.
- Introduction
- Electrovalency
- Covalency
- General Properties Of Ionic And Covalent Bonds
- CO-Ordinate Covalency
- Hybridization
- Vsepr Theory (Valence Shell Electron Pair Repulsion Theory)
- Rule For Determination Of Total Number Of Hybrid Orbitals
- Resonance
- Rules For Writing Resonating Structures
- Deviation From Ideal Behavior
- Factors Governing Polarization And Polarisability (Fajan's Rule)
- Dipole Moment In Aromatic Ring System
- Percentage Of Iconic Character
- Hydrogen Bonding
- Types Of Hydrogen Bonding
- Effect Of Hydrogen Bonding
- Importance Of Hydrogen Bonding In Biological Systems
- Intermolecular-Forces
- Molecular Orbital Theory
- Inert Pair Effect
- Back Bonding
- Exercise 1
- Exercise 2
- Exercise 3
- Exercise 4
- Exercise 5
