1. What is the Clausius-Clapeyron Equation?

The Clausius-Clapeyron equation describes the relationship between vapor pressure and temperature for a substance. It is used to calculate the boiling point at different pressures, which is particularly useful in chemical engineering and thermodynamics applications.

2. How Does the Calculator Work?

The calculator uses the Clausius-Clapeyron equation:

Where:

• \( T_1 \) — Initial temperature (K)
• \( R \) — Gas constant (J/mol·K)
• \( P_2 \) — New pressure (Pa)
• \( P_1 \) — Initial pressure (Pa)
• \( \Delta H_v \) — Enthalpy of vaporization (J/mol)

Explanation: The equation calculates the new boiling point temperature when pressure changes, based on the thermodynamic properties of the substance.

3. Importance of Boiling Point Calculation

Details: Accurate boiling point calculation at different pressures is crucial for process design in chemical industries, distillation operations, and understanding phase behavior of substances under varying conditions.

4. Using the Calculator

Tips: Enter all values in the specified units. Temperature must be in Kelvin, pressure in Pascals, and enthalpy in J/mol. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical value for gas constant R?
A: The universal gas constant is typically 8.314 J/mol·K for most calculations.

Q2: Can this equation be used for all substances?
A: The equation works best for substances where the enthalpy of vaporization is relatively constant over the temperature range of interest.

Q3: What are common units for pressure conversion?
A: 1 atm = 101325 Pa, 1 bar = 100000 Pa, 1 mmHg = 133.322 Pa

Q4: How accurate is this calculation?
A: The accuracy depends on the constancy of ΔH_v. For large pressure differences, the calculation may be less accurate.

Q5: Can this be used for sublimation points?
A: Yes, with appropriate modification using enthalpy of sublimation instead of vaporization.