heat of fusion
Học thuậtThân thiện
Definition
- Noun:
- The amount of heat energy required to change a unit mass of a substance from a solid to a liquid at its melting point, without changing its temperature. This is a specific physical property of a substance. The same amount of energy is released when the liquid solidifies (heat of solidification).
Usage
- Heat of fusion is a scientific term used primarily in physics and chemistry.
- It is used when discussing phase changes, thermal energy calculations, and material properties.
- It is often represented by the symbol ΔH_f.
Examples
- The heat of fusion of ice is 334 joules per gram. This means 334 J are needed to melt 1 gram of ice at 0°C into water at 0°C.
- To design the cooling system, engineers must consider the heat of fusion of the material used for thermal storage.
- A high heat of fusion explains why melting a large amount of metal requires a significant input of energy from the furnace.
Advanced Usage
- "Latent heat of fusion": This is a more precise synonym, emphasizing that the heat energy is "hidden" as it changes the substance's state without changing its temperature.
- The latent heat of fusion for water is a key factor in regulating Earth's climate.
- The concept is crucial in calorimetry equations: Q = m * ΔHf, where Q is heat, m is mass, and ΔHf is the heat of fusion.
Variants and Related Words
- Heat of solidification (n): The heat released when a unit mass of a liquid solidifies at its freezing point. It is numerically equal to the heat of fusion.
- Heat of vaporization (n): The amount of heat required to change a unit mass of a liquid into a gas at its boiling point.
- Latent heat (n): The general term for heat absorbed or released during a phase change at constant temperature (includes fusion and vaporization).
- Enthalpy of fusion (n): A thermodynamic term essentially synonymous with heat of fusion, often used in more formal chemical contexts.
Synonyms
- Latent heat of fusion
- Enthalpy of fusion (in thermodynamics)
Related Scientific Concepts
- Phase change: The physical process (melting, freezing, vaporization, condensation) during which heat of fusion or vaporization is involved.
- Specific heat capacity: The heat required to raise the temperature of a unit mass by one degree, distinct from the heat required for a phase change.
- Thermodynamics: The branch of physics that deals with heat, work, and energy, where the concept of heat of fusion is formally defined.
Noun
- heat absorbed by a unit mass of a solid at its melting point in order to convert the solid into a liquid at the same temperature
- the heat of fusion is equal to the heat of solidification