Liquids - Vapor Pressures
Vapor and saturation pressure for some common liquids. The vapor pressure of a liquid is defined as the pressure exerted by the molecules that escape from the liquid to form a separate vapor phase above the liquid surface.
Vapor Pressure Reference
The vapor pressure of a liquid is the pressure exerted by molecules that escape from the liquid to form a separate vapor phase above the liquid surface.
Key Information
- Vapor or saturation pressure depends on temperature
- For solutions with multiple components:
- Higher vapor pressure components are called light components
- Lower vapor pressure components are called heavy components
Common Saturation Temperatures at Atmospheric Pressure
- Water: 100°C (212°F)
- Ethyl alcohol: 78.5°C (173°F)
Data Reference
The vapor pressure table below shows approximate values for temperatures in the range 20°C - 25°C (68°F - 77°F).
Conversion: 1 kPa = 103 Pa = 0.145 psi