Temperature - Pressure - Volume
WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.
Evaporation temperature, condensation temperature
The temperature at which a liquid begins to boil depends not only on which liquid it is, but also on the pressure.
Water for example, begins to boil and evaporate at 100°C (212°F) at normal air pressure (÷ 1 bar).
In order for the water to be able to boil and evaporate, the pressure of the steam must be higher than the air pressure.
This means that if the air pressure is increased, the boiling point also increases. Conversely of the pressure is reduced, the boiling point is lowered.
For example water boils at:
- 180°C (356°F) if the pressure is 10 bar.
- 20°C (68°F) if there is a negative pressure of 0.97 bar.
Changes in volume
The following applies to all gases:
- when the volume is reduced, pressure and temperature increases.
- when the volume is increases, pressure and temperature is reduced.
A change in volume also effects the evaporation and condensation temperatures.