Temperature Pressure Boiling Point Calculator

Clausius-Clapeyron Equation:

\[ T_b = \frac{1}{\frac{1}{T_0} - \frac{R}{\Delta H_{vap}} \ln \left( \frac{P}{P_0} \right)} \]

Reference Temperature (T₀):

Enthalpy of Vaporization (ΔHvap):

J/mol

Pressure (P):

Reference Pressure (P₀):

Boiling Point (Tb):

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1. What is the Clausius-Clapeyron Equation?

The Clausius-Clapeyron equation describes the relationship between temperature and pressure at phase transitions, particularly for vaporization. It allows calculation of boiling points at different pressures based on known reference values.

2. How Does the Calculator Work?

The calculator uses the Clausius-Clapeyron equation:

\[ T_b = \frac{1}{\frac{1}{T_0} - \frac{R}{\Delta H_{vap}} \ln \left( \frac{P}{P_0} \right)} \]

Where:

\( T_b \) — Boiling point at pressure P (K)
\( T_0 \) — Reference temperature (K)
\( R \) — Gas constant (8.314 J/mol·K)
\( \Delta H_{vap} \) — Enthalpy of vaporization (J/mol)
\( P \) — Pressure (Pa)
\( P_0 \) — Reference pressure (Pa)

Explanation: The equation calculates how boiling temperature changes with pressure, accounting for the energy required for vaporization.

3. Importance of Boiling Point Calculation

Details: Accurate boiling point prediction is crucial for chemical engineering processes, distillation design, pharmaceutical manufacturing, and understanding atmospheric phenomena.

4. Using the Calculator

Tips: Enter all values in SI units. Temperature in Kelvin, enthalpy in J/mol, pressure in Pascals. All values must be positive and non-zero.

5. Frequently Asked Questions (FAQ)

Q1: Why use Kelvin instead of Celsius?
A: The equation requires absolute temperature for thermodynamic calculations, making Kelvin the appropriate unit.

Q2: What is a typical ΔHvap value?
A: For water at 100°C, ΔHvap is approximately 40.7 kJ/mol. Values vary significantly between different substances.

Q3: Can this be used for other phase transitions?
A: The equation can be adapted for sublimation and fusion, though ΔH values and applicability may differ.

Q4: What are the limitations of this equation?
A: It assumes constant ΔHvap and ideal gas behavior, which may not hold over large temperature ranges.

Q5: How accurate is this calculation?
A: It provides good estimates for many applications, but experimental validation is recommended for precise engineering work.