Water has an unusually high boiling point
The boiling point of water at 100 degrees Celsius is anomalously high compared to similar hydrides.
Scientific Explanation
Water boils at 100 degrees Celsius — a value so ingrained in our thinking that we rarely question it. But when compared to the boiling points of related molecules, the anomaly becomes striking: hydrogen sulfide (H2S) boils at minus 60 degrees Celsius, hydrogen selenide (H2Se) at minus 41 degrees Celsius, and even the much heavier hydrogen telluride (H2Te) boils at just minus 2 degrees Celsius.
Why is water’s boiling point so much higher? The answer, once again, lies in hydrogen bonds. In liquid water, each molecule forms a dynamic network of hydrogen bonds with its neighbors. To bring water to a boil, enough of these bonds must be broken so that individual molecules can escape into the gas phase. The energy required for this — the enthalpy of vaporization — is about five times higher for water than for H2S.
If you extrapolate the trend from the heavier hydrides back to the lightest member of the group, water should boil at around minus 80 degrees Celsius. Instead, the boiling point is nearly 180 degrees higher — an enormous difference entirely attributable to the strength of intermolecular hydrogen bonding.
Everyday Relevance
Without this high boiling point, Earth would be a fundamentally different planet. Water would exist as a gas at room temperature — no oceans, no lakes, no rain. The entire weather system of our planet depends on water cycling between liquid and vapor, transporting enormous amounts of energy in the process.
In daily life, we constantly benefit from this property: we can heat water in a pot without it vanishing instantly. Cooking, steaming, brewing tea — all of this would be impossible if water had a “normal” boiling point. And our bodies exploit the high enthalpy of vaporization for cooling: when sweat evaporates, it draws a large amount of heat from the skin — an exceptionally efficient cooling mechanism.