Hydrogen Bonding
Explains the formation of hydrogen bonds, their types (intermolecular, intramolecular), and their effects on physical properties.
What is Hydrogen Bonding?
A weak electrostatic attraction between a hydrogen atom covalently bonded to a highly electronegative atom (F, O, or N) and an electron pair on another electronegative atom in a different molecule or within the same molecule.
Key points
- Define hydrogen bonding and its conditions.
- Differentiate between intermolecular and intramolecular hydrogen bonding.
- Explain the factors affecting the strength of hydrogen bonds.
- Relate hydrogen bonding to the physical properties of substances.
Common exam trap
Confusing hydrogen bonding with covalent bonding.
Definitions
- Term
Hydrogen Bond
- Meaning
A weak electrostatic attraction between a hydrogen atom covalently bonded to a highly electronegative atom (F, O, or N) and an electron pair on another electronegative atom in a different molecule or within the same molecule.
- Term
Intermolecular Hydrogen Bond
- Meaning
A hydrogen bond formed between hydrogen atoms of one molecule and electronegative atoms of different molecules.
- Term
Intramolecular Hydrogen Bond
- Meaning
A hydrogen bond formed between hydrogen atoms and electronegative atoms within the same molecule.
Learning objectives
Define hydrogen bonding and its conditions.
Differentiate between intermolecular and intramolecular hydrogen bonding.
Explain the factors affecting the strength of hydrogen bonds.
Relate hydrogen bonding to the physical properties of substances.
Identify examples of molecules exhibiting hydrogen bonding.
Prerequisites
Electronegativity
Polar covalent bonds
Intermolecular forces (dipole-dipole interactions)
Molecular structure
Common mistakes
Confusing hydrogen bonding with covalent bonding.
Assuming H-bonding occurs with any H atom, ignoring the electronegativity of the attached atom.
Not distinguishing between intermolecular and intramolecular H-bonding.
Overestimating the strength of H-bonds compared to covalent bonds.
Keywords
Hydrogen bond
Intermolecular force
Electronegativity
Polarity
Dipole-dipole interaction
Boiling point
Water
HF
NH3
Intramolecular
Practice preview
Which of the following substances exhibits the strongest hydrogen bonding?…
easy
Intramolecular hydrogen bonding is observed in:…
medium
Which of the following is an example of intermolecular hydrogen bonding?…
medium