What Is the Raoult's Law Vapor Pressure Depression Calculator?
Raoult's Law was established by French chemist François-Marie Raoult in 1887 and explains colligative solvent depression.
How Does the Raoult's Law Vapor Pressure Depression Calculator Work?
Solute particles occupy surface area at the liquid-gas interface, reducing the rate at which solvent molecules escape into the vapor phase.
Raoult's Law Vapor Pressure Depression Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
P_{\text{solution}} = \chi_{\text{solvent}} \cdot P^{\circ}, \quad \Delta P = P^{\circ} - P
Solution vapor pressure equals solvent mole fraction times pure solvent vapor pressure.
How to Use the Raoult's Law Vapor Pressure Depression Calculator
- Input pure solvent vapor pressure in kPa or mmHg.
- Enter solvent mole fraction (0 to 1).
Step-by-Step Example Calculation
Aqueous Sugar Solution Vapor Depression
Input Values:
purePressure:3.17
moleFraction:0.95
Worked Steps: In a solution with 0.95 mole fraction water at 25°C, vapor pressure depresses from 3.17 kPa to 3.01 kPa (ΔP = 0.16 kPa).
Understanding Your Result
Solution Vapor Pressure: Reduced equilibrium headspace pressure.
Vapor Pressure Lowering (ΔP): Absolute pressure drop.
Factors That Affect the Result
- Solute concentration and solvent purity.
When Should You Use This Calculator?
- Chemical distillation column engineering and thermodynamic phase equilibria.
Assumptions & Limitations
- Assumes non-volatile solute and ideal thermodynamic mixing.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Standard thermodynamic formulation for ideal dilute solutions.