Calculator Inputs
Use Antoine constants for two components, choose a mode, then calculate bubble or dew conditions. The calculator accepts bar/K or mmHg/°C Antoine forms.
Example Data Table
Example values below use benzene and toluene with Antoine constants in the bar/K form. These examples help verify data entry and expected outputs.
| Mode | Basis Input | Calculated Output | Notes |
|---|---|---|---|
| Bubble pressure | T = 95 °C, x1 = 0.40 | P = 100.8938 kPa, y1 = 0.6219 | Benzene richer in vapor phase. |
| Dew pressure | T = 95 °C, y1 = 0.55 | P = 94.4840 kPa, x1 = 0.3313 | Liquid phase is leaner in benzene. |
| Bubble temperature | P = 101.325 kPa, x1 = 0.40 | T = 97.3904 °C, y1 = 0.5480 | Boiling starts at this temperature. |
| Dew temperature | P = 101.325 kPa, y1 = 0.55 | T = 97.3323 °C, x1 = 0.3330 | Condensation starts at this temperature. |
Formula Used
Antoine equation
For bar/K input: log10(Psat) = A − B / (TK + C). For mmHg/°C input: log10(Psat) = A − B / (TC + C).
Raoult law
For each component, yi P = xi Psat,i. This assumes an ideal liquid phase and low-pressure ideal vapor behavior.
Bubble pressure
P = x1 Psat,1 + x2 Psat,2 and y1 = x1 Psat,1 / P.
Dew pressure
1 / P = y1 / Psat,1 + y2 / Psat,2 and x1 = y1 P / Psat,1.
Bubble temperature
Solve x1 Psat,1(T) + x2 Psat,2(T) = P using a bisection root finder.
Dew temperature
Solve y1 P / Psat,1(T) + y2 P / Psat,2(T) = 1 using a bisection root finder.
How to Use This Calculator
- Enter the names of the two components.
- Select the Antoine basis that matches your constants.
- Type Antoine A, B, and C values for both components.
- Choose bubble pressure, dew pressure, bubble temperature, or dew temperature mode.
- Enter the known temperature or pressure.
- Provide the component 1 composition as x1 for bubble mode or y1 for dew mode.
- For temperature solving modes, set realistic minimum and maximum temperatures.
- Click the calculate button to show results above the form.
- Use the export buttons to save CSV or PDF reports.
Frequently Asked Questions
1. What does this calculator solve?
It solves bubble pressure, dew pressure, bubble temperature, and dew temperature for a binary mixture under ideal vapor liquid equilibrium assumptions.
2. Which thermodynamic model is used?
The calculator uses Antoine vapor pressure relations and Raoult law. It is best for ideal or nearly ideal liquid mixtures at moderate pressures.
3. Can I use textbook Antoine constants?
Yes. Choose the correct Antoine basis first. The calculator supports constants expressed in bar with Kelvin or in mmHg with Celsius.
4. Why do temperature modes need bounds?
Bubble and dew temperature problems are solved numerically. Reasonable lower and upper temperature limits help the solver find the correct equilibrium root.
5. What is the difference between x1 and y1?
x1 is the liquid-phase mole fraction of component 1. y1 is the vapor-phase mole fraction of component 1 at equilibrium.
6. What do K values mean here?
Each K value equals Psat divided by system pressure for the ideal model. Larger K usually means stronger volatility into the vapor phase.
7. When should I avoid this tool?
Avoid it for strongly nonideal systems, azeotropes, high-pressure systems, or cases requiring activity coefficients, equations of state, or fugacity corrections.
8. What can I export?
You can export a summary report and the equilibrium sweep table as CSV or PDF for reports, design reviews, and class assignments.