Vapor Pressure Calculator

Our vapor pressure calculator simplifies complex thermodynamic calculations. Whether you’re a student learning chemistry basics or a professional designing industrial processes, this tool provides accurate, reliable results.

How Vapor Pressure Calculator Works

Our calculator uses the proven Clausius-Clapeyron equation to find unknown vapor pressures or temperatures. The formula looks like this:

P₂ = P₁ × exp((ΔH/R)(1/T₁-1/T₂))

Don’t worry about the complex math. This calculator handles everything automatically. You just enter the known values, and it calculates the unknown value for you.

Step-by-Step Guide to Using the Calculator

Following the given step to use Vapour Pressure Calculator:

What You Need Before Starting

Gather these values before using the calculator:

• Temperature at one point (in Kelvin)
• Vapor pressure at that temperature (in atm)
• Temperature at another point (in Kelvin)
• Molar enthalpy of vaporization (in joule/mole)

Input Process

1. Choose Your Unknown: Select what you want to calculate by entering ‘x’ in that field
2. Enter Known Temperature: Input the temperature where you know the vapor pressure
3. Enter Known Vapor Pressure: Input the corresponding pressure value
4. Enter Second Temperature: Input the temperature where you want to find pressure
5. Enter Enthalpy Value: Input the molar enthalpy of vaporization
6. Click Calculate: Press the blue “Calculate x” button

The calculator instantly shows your result in the answer box.

Practical Examples and Applications

Example 1: Finding Water’s Vapor Pressure

Let’s say you know water has a vapor pressure of 1 atm at 373.15 K (100°C). You want to find its vapor pressure at 298.15 K (25°C).

Input Values:

• P₁ = 1 atm
• T₁ = 373.15 K
• T₂ = 298.15 K
• ΔH = 40,660 J/mol
• P₂ = x (unknown)

Result: The calculator shows P₂ = 0.0317 atm

Frequently Asked Questions