Clausius-Clapeyron Equation Calculator
The Clausius-Clapeyron Equation Calculator is designed for advanced chemistry students and professionals who need to calculate phase transition properties. This tool helps solve problems related to phase changes in substances.
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Data Source and Methodology
All calculations are based strictly on the Clausius-Clapeyron equation as described in standard chemistry textbooks. Ensure data accuracy by consulting reliable scientific sources.
The Formula Explained
\[ \ln\left(\frac{P2}{P1}\right) = \frac{\Delta Hvap}{R} \left(\frac{1}{T1} - \frac{1}{T2}\right) \]
Where \( R = 8.314 \, \text{J/mol·K} \) is the gas constant.
Glossary of Terms
- T1: Initial temperature in Kelvin.
- T2: Final temperature in Kelvin.
- ΔHvap: Enthalpy of vaporization in Joules per mole.
- P2/P1: Pressure ratio between final and initial states.
How It Works: A Step-by-Step Example
Consider a substance with an initial temperature (T1) of 300 K and a final temperature (T2) of 350 K, with an enthalpy of vaporization (ΔHvap) of 40,000 J/mol. Using the Clausius-Clapeyron equation, the pressure ratio \( P2/P1 \) can be calculated.
Frequently Asked Questions (FAQ)
What is the Clausius-Clapeyron equation used for?
It is used to describe the phase transition between two phases of matter, such as liquid to gas.
Why are temperatures required in Kelvin?
Kelvin is the absolute temperature scale used in thermodynamic equations to ensure proportionality and accuracy.
How does ΔHvap affect the calculation?
The enthalpy of vaporization directly influences the pressure change; higher values indicate more energy required for phase change.
Can this calculator be used for all substances?
Yes, provided you have the necessary input values like temperature and enthalpy of vaporization.
Where can I find reliable ΔHvap values?
Consult scientific literature or databases for accurate enthalpy values specific to each substance.
Formula (LaTeX) + variables + units
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\ln\left(\frac{P2}{P1}\right) = \frac{\Delta Hvap}{R} \left(\frac{1}{T1} - \frac{1}{T2}\right)
\[ \ln\left(\frac{P2}{P1}\right) = \frac{\Delta Hvap}{R} \left(\frac{1}{T1} - \frac{1}{T2}\right) \] Where \( R = 8.314 \, \text{J/mol·K} \) is the gas constant.
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- NIST — Weights and measures — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/weights-and-measures - FTC — Consumer advice — consumer.ftc.gov · Accessed 2026-01-19
https://consumer.ftc.gov/
Last code update: 2026-01-19
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