Latent Heat of Vaporization Calculator
Solve heat, mass, or latent values accurately. Apply efficiency, cycles, presets, and unit conversions easily. See visual trends, downloads, examples, and clear reporting tools.
Calculator Form
Use the responsive input grid below. Large screens show 3 columns, smaller screens show 2 columns, and mobile shows 1 column.
Formula Used
For vaporization, the useful phase-change heat is the product of mass and latent heat of vaporization.
- Q = energy involved in the phase change.
- m = mass vaporized in one cycle.
- Lv = latent heat of vaporization.
- n = number of repeated cycles.
- η = efficiency written as a decimal, so 85% becomes 0.85.
How to Use This Calculator
- Select what you want to solve: energy, mass, or latent heat.
- Choose a material preset or keep the input fully custom.
- Enter the known values with your preferred units.
- Set efficiency if your system loses energy during heating.
- Add the number of cycles for repeated identical batches.
- Press Calculate to show the result above the form.
- Review the result table, graph, and download options.
Example Data Table
These example values are illustrative and use approximate latent heat data for common substances.
| Material | Mass (kg) | Latent Heat (kJ/kg) | Ideal Heat (kJ) | Efficiency | Actual Input (kJ) |
|---|---|---|---|---|---|
| Water | 1.00 | 2257 | 2257.0 | 90% | 2507.8 |
| Ethanol | 0.75 | 846 | 634.5 | 90% | 705.0 |
| Ammonia | 0.50 | 1370 | 685.0 | 90% | 761.1 |
| Acetone | 1.20 | 518 | 621.6 | 90% | 690.7 |
Frequently Asked Questions
1) What is latent heat of vaporization?
It is the heat needed to convert a liquid into vapor without changing temperature. The energy breaks intermolecular attraction during the phase change.
2) Why does this calculator include efficiency?
Real systems lose heat through walls, piping, air, and imperfect transfer. Efficiency helps estimate the actual input energy needed beyond the ideal phase-change energy.
3) Does boiling temperature affect the basic formula?
The core relation remains Q = m × Lv. However, the actual latent heat value depends on the substance and conditions, so use an appropriate reference value.
4) Can I use calories instead of joules?
Yes. The calculator supports joules, kilojoules, megajoules, calories, and kilocalories for energy, plus several latent heat unit options.
5) Is the mass result per cycle or total?
This calculator reports mass vaporized per cycle and also shows total mass across all cycles. That makes repeated-batch analysis easier and clearer.
6) Why might my measured value differ from a table value?
Differences can come from pressure, impurities, measurement error, incomplete vaporization, or energy losses. Reference tables often assume controlled conditions and idealized behavior.
7) Can this tool estimate repeated evaporation batches?
Yes. Enter the number of cycles and the calculator scales total useful heat, total input energy, and total evaporated mass accordingly.
8) What does the graph show?
The graph compares useful heat total, actual input total, and actual input per cycle. It helps visualize loss effects and batch scaling.