Hydrogen Bonding in Detail

Hydrogen bonding is the most important intermolecular force in chemistry and biology. While the previous lesson introduced the basic concept, this lesson explores the profound consequences of hydrogen bonding — from the anomalous properties of water to the structure of DNA. Understanding these applications is essential for A-Level Chemistry.

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Why Water Is Anomalous

Water is often described as the most anomalous compound known. Its properties deviate dramatically from what we would predict based on its molecular mass alone, and almost all of these anomalies are explained by hydrogen bonding.

Anomalously High Boiling Point

If we extrapolate the trend in boiling points of Group 6 hydrides (H₂Te → H₂Se → H₂S), we would predict that H₂O should boil at approximately −80°C. Instead, it boils at 100°C — about 180°C higher than expected.