CHEMITRY CALCULATOR
Vapor Pressure
A precise tool.
What is the Vapor Pressure & How does it work?
Vapor pressure is the pressure exerted by a vapor in thermodynamic equilibrium with its liquid or solid phase.
The Clausius-Clapeyron equation relates the vapor pressure of a substance to its temperature. It is expressed as:
lnleft(frac{P_2}{P_1}right) = frac{-Delta H_{vap}}{R} left(frac{1}{T_2} – frac{1}{T_1}right)
P = vapor pressure, Delta H_{vap} = enthalpy of vaporization, R = gas constant, T = temperature in Kelvin
This equation is useful for predicting how the vapor pressure of a substance changes with temperature.
Parameters
Result
—
Frequently Asked Questions
What is vapor pressure?
Vapor pressure is the pressure exerted by a vapor in equilibrium with its liquid or solid phase.
How does the Clausius-Clapeyron equation work?
The equation relates vapor pressure to temperature, enthalpy of vaporization, and the gas constant.
What units should I use for temperature in this calculator?
Temperature should be entered in Kelvin.
Can I use Celsius instead of Kelvin?
No, you must convert Celsius to Kelvin by adding 273.15 to the Celsius value.
What is the gas constant R used in the equation?
The gas constant R is approximately 8.314 J/(mol·K).
How do I find the enthalpy of vaporization for a substance?
You can look up the enthalpy of vaporization in thermodynamic tables or databases.
What is the Clausius-Clapeyron equation used for?
It’s used to predict how vapor pressure changes with temperature for a given substance.
Results are for informational purposes only and do not constitute professional advice.