Latent energy magnitude
Energy magnitude during phase change only.
Thermal engineering · Thermodynamics
Latent heat calculator
Find the energy magnitude, transformed mass or specific latent heat in Q = mL. The model isolates a phase change and does not include heating or cooling before or after the transition.
Created v1.0
By Thibaut Grzelak, Mechanical Analysis Engineer
02
Results
Transformed mass
Mass undergoing the specified phase change.
Specific latent heat
Energy magnitude per transformed mass.
Relation and numerical substitution
Q = mL—
A specified transition at appropriate pressure and temperature, with a positive constant latent heat supplied by the user.
01Formulas and symbols
Formulas used
Q
Q = m × LEnergy magnitude during phase change only.m
m = Q / LMass undergoing the specified phase change.L
L = Q / mEnergy magnitude per transformed mass.02Assumptions and limits
Scope of validity
- A specified transition at appropriate pressure and temperature, with a positive constant latent heat supplied by the user.
03Validation example
Reference numerical case
- m = 2 kg and L = 334000 J/kg give Q = 668000 J = 668 kJ. L is supplied for this example, not selected automatically.
04References
Technical references
- University Physics 2, §1.5 Phase changes — OpenStax
FAQ
Does Q = mL include warming the solid?
No. Add the sensible energy mcΔT separately before or after the phase-change stage.
Why is Q displayed positive for freezing too?
This calculator reports magnitude. Freezing releases energy to the surroundings; melting absorbs the same magnitude under the ideal stated conditions.
05Model and conventions
Find the energy magnitude, transformed mass or specific latent heat in Q = mL. The model isolates a phase change and does not include heating or cooling before or after the transition.
06Limits of this model
No material database or partial multistage heat balance. The reverse transition releases the same energy magnitude in this ideal model. Use sensible heat for temperature changes.
07Common mistakes
L is energy per mass, not specific heat capacity. Select J/kg or kJ/kg carefully; the main Q is a nonnegative magnitude.