Vapor pressure of water

Definition

Vapor pressure of water is the pressure exerted by water vapor in equilibrium with its liquid or solid phase at a given temperature. It increases with temperature as more molecules escape the liquid phase into the vapor phase.

5 Must Know Facts For Your Next Test

1. Vapor pressure of water depends on temperature; it increases as temperature increases.
2. At 100°C, the vapor pressure of water equals atmospheric pressure (1 atm), leading to boiling.
3. The Clausius-Clapeyron equation can be used to relate vapor pressure and temperature.
4. In calculations involving gas mixtures, the partial pressure of water vapor must be considered.
5. Vapor pressure lowering occurs when a non-volatile solute is dissolved in water, according to Raoult's Law.

Related terms

Partial Pressure:

The pressure exerted by a single component of a mixture of gases.

Boiling Point:

The temperature at which a liquid's vapor pressure equals external atmospheric pressure.

Raoult's Law:

$P_{solution} = X_{solvent} \times P^0_{solvent}$; it states that the partial vapor pressure of each volatile component in a solution is equal to the product of the mole fraction of the solvent and its pure component vapor pressure.