Boiling Point Calculator
Calculate boiling point at any pressure using the Clausius-Clapeyron equation
Calculate Boiling Point
Reference State (Known Conditions)
Standard atmospheric pressure: 1013.25 hPa
Water boils at 100°C at standard pressure
Target State (Calculate Boiling Point)
Boiling Point Results
Clausius-Clapeyron Equation: ln(P₁/P₂) = -ΔH/R × (1/T₁ - 1/T₂)
Analysis:
Quick Examples
Water at Sea Level
Pressure: 1013.25 hPa
Boiling Point: 100°C
Standard reference conditions
Water at High Altitude
Pressure: 700 hPa (3000m)
Boiling Point: ~90°C
Lower pressure = lower boiling point
Pressure Cooker
Pressure: 2026 hPa (2 atm)
Boiling Point: ~121°C
Higher pressure = higher boiling point
Common Substances
*At standard atmospheric pressure
Understanding Boiling Point and Pressure Relationships
What is Boiling Point?
The boiling point is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid, causing it to change from liquid to gas phase. This temperature depends on both the substance's properties and the external pressure.
Clausius-Clapeyron Equation
ln(P₁/P₂) = -ΔH/R × (1/T₁ - 1/T₂)
- P₁, P₂: Pressures at states 1 and 2
- T₁, T₂: Temperatures at states 1 and 2 (Kelvin)
- ΔH: Heat of vaporization (J/mol)
- R: Gas constant (8.314 J/(mol·K))
Pressure Effects
Higher Pressure
Increases boiling point. Molecules need more energy to overcome higher external pressure.
Lower Pressure
Decreases boiling point. Less external pressure makes vaporization easier.
Standard Conditions
1 atm (1013.25 hPa) at sea level. Reference point for most boiling point data.
Real-World Applications
- • Cooking at high altitudes (lower pressure, longer cooking times)
- • Pressure cookers (higher pressure, faster cooking)
- • Vacuum distillation (lower pressure, gentler separation)
- • Industrial processes requiring specific temperatures
Important Considerations
Heat of Vaporization
Each substance has a unique heat of vaporization that affects how much the boiling point changes with pressure
Temperature Units
Always use absolute temperature (Kelvin) in calculations, but results can be displayed in any unit
Accuracy Limits
The equation is most accurate for pure substances and moderate pressure changes