What is Hydrogen Bond?
A hydrogen bond is a type of electrostatic force of attraction between a hydrogen atom and another electronegative atom. It is a type of intermolecular force. The hydrogen atom is covalently bonded to a more electronegative “donor” atom or group, and the other atom has a lone pair of electrons. The hydrogen atom is called the H-bond donor, and the other atom is called the H-bond acceptor.
Hydrogen bonds are weak, intermolecular bonds that hold together soft matter, water, network liquids, and many ferroelectric crystals. For example, water is a liquid over a wider range of temperatures than expected for its size because of its extensive hydrogen bonding. Water is also a good solvent for ionic compounds and many others because it readily forms hydrogen bonds with the solute.
Formation of Hydrogen Bonds
Hydrogen bonds form when a hydrogen atom that is covalently bonded to an electronegative atom (such as oxygen, nitrogen, or fluorine) interacts with another electronegative atom nearby. The formation of hydrogen bonds is illustrated as follows:
- Polar Covalent Bond: Initially, there is a polar covalent bond between a hydrogen atom (H) and an electronegative atom (let’s say oxygen, O). In a water molecule (H2O), for example, each hydrogen atom forms a polar covalent bond with the oxygen atom.
- Electronegativity Difference: Oxygen is more electronegative than hydrogen. As a result, the shared electrons in the covalent bond spend more time around the oxygen nucleus, creating a partial negative charge (δ−) on the oxygen atom and a partial positive charge (δ+) on the hydrogen atom.
- Attraction between Opposite Charges: The partial positive charge on the hydrogen atom in one molecule is attracted to the partial negative charge on the electronegative atom of another molecule. For example, the partial positive charge on the hydrogen atom of one water molecule is attracted to the partial negative charge on the oxygen atom of another water molecule.
- Formation of Hydrogen Bond: This electrostatic attraction between the partially positive hydrogen atom and the partially negative atom of another molecule is known as a hydrogen bond. Although individually weaker than covalent or ionic bonds, hydrogen bonds collectively play crucial roles in various biological and chemical processes, such as the structure of DNA, the properties of water, and protein folding.
In short, hydrogen bonds form due to the attraction between the partial positive charge on a hydrogen atom and the partial negative charge on an electronegative atom of another molecule, leading to the formation of a weak electrostatic bond between the molecules.
Hydrogen Bonding
In chemistry, a hydrogen bond is an electrostatic force of attraction between a hydrogen atom and another electronegative atom. It is a special type of dipole-dipole force. Hydrogen bonding is the phenomenon of the formation of Hydrogen Bonds.
H Bonds are stronger than any dipole-dipole bonds but weaker than covalent bonds. Hydrogen bonds can form between atoms within a molecule or between two different molecules.
Hydrogen bonds can form when:
- A hydrogen atom is covalently bonded to a more electronegative atom
- The other atom has a lone pair of electrons
Examples of hydrogen bonds Water, Ammonia, and Hydrogen Fluoride.
Table of Content
- What is Hydrogen Bond?
- What is Hydrogen Bonding?
- Important Conditions for Hydrogen Bonding
- Effects of Hydrogen Bonding on Elements
- Examples of Hydrogen Bonding
- Properties of Hydrogen Bonding
- Types of Hydrogen Bonding
- Difference between a Hydrogen Bond and Covalent Bond
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