Latent Heat (Q = mL)
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Q = mL
What each symbol means
| Symbol | What it stands for |
|---|---|
| L | Specific latent heat (J kg⁻¹) |
| Q | Heat energy required for phase change (J) |
| m | Mass of the substance (kg) |
When to use this
Temperature remains constant during phase change. Lf = latent heat of fusion (solid ↔ liquid), Lv = latent heat of vaporisation (liquid ↔ gas). For water: Lf = 3.33 × 10⁵ J/kg, Lv = 22.6 × 10⁵ J/kg. Burns from steam are worse than boiling water because steam carries Lv extra energy.