# melting point

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## melting point,

temperaturetemperature,
measure of the relative warmth or coolness of an object. Temperature is measured by means of a thermometer or other instrument having a scale calibrated in units called degrees. The size of a degree depends on the particular temperature scale being used.
at which a substance changes its state from solid to liquid. Under standard atmospheric pressure different pure crystalline solids will each melt at a different specific temperature; thus melting point is a characteristic of a substance and can be used to identify it. When heat is applied continuously and in sufficient quantity to such solids, the temperature rises steadily until it reaches the point at which liquefaction occurs. Here the rise ceases and no further change in temperature is observed until all of the substance has been converted to liquid. The heat being applied to the substance at that temperature is consumed in bringing about the change of state, and none is available to raise the temperature of that part of the substance already liquefied until all of it has changed to the liquid. If heat is still applied when liquefaction is complete, the temperature will begin to rise again. The quantity of heat necessary to change one gram of any substance from solid to liquid at its melting point is known as its latent heatlatent heat,
heat change associated with a change of state or phase (see states of matter). Latent heat, also called heat of transformation, is the heat given up or absorbed by a unit mass of a substance as it changes from a solid to a liquid, from a liquid to a gas, or the
of fusion and differs for different substances. Ice, for example, requires approximately 80 calories of heat to change each gram to water at its melting point. Because its heat of fusion is relatively high, ice is used in refrigeration. In freezing (the reverse process, i.e., the change from liquid to solid), heat is given off by the substance undergoing the change, and the amount given off is the same as that absorbed in melting.

## Melting Point

(mp), the temperature of the equilibrium phase transition of a crystalline (solid) body to liquid at a constant external pressure. The melting point is a particular case of the temperature of the first-order phase transition. The melting points of several substances at standard pressure (760 mm Hg, or 101,325 newtons per m2) are shown in Table 1.

Table 1
Substancemp (°C)
Hydrogen ...............–259.14
Oxygen ...............–218.4
Nitrogen ...............– 209.86
Argon ...............–189.2
Ethyl alcohol ...............–112.0
Methyl alcohol ...............–97.8
Acetone ...............–94.6
Mercury ...............–38.9
Ethylone glycol ...............–15.6
Nitrobenzene ...............5.7
Acetic acid ...............16.7
Glycerine ...............17.9
Cesium ...............28.5
Naphthalene ...............80.2
Sodium ...............97.8
Iodine ...............112.9
D-Camphor ...............178.5
Aluminum ...............660.37
Copper ...............1083.4
Iron ...............1539.0
Tungsten ...............3410.0

## melting point

[′melt·iŋ ‚pȯint]
(thermodynamics)
The temperature at which a solid of a pure substance changes to a liquid. Abbreviated mp.
For a solution of two or more components, the temperature at which the first trace of liquid appears as the solution is heated.

## melting point

the temperature at which a solid turns into a liquid. It is equal to the freezing point
References in periodicals archive ?
The equilibrium melting point of PHO was determined to be approximately 68[Degrees].
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When new Ingeo 6100D is compared to the existing Ingeo grade 6202D, one of the most often applied grades for fibers and spunbond nonwovens, NatureWorks scientists found: Peak melting point increased by 8CEs from 164Es to 172Es; melting shoulder increased by 15CEs; fiber crystallinity increased by ~20%; quiescent crystallization rate increased three to four times; and lower stress required for stress induced crystallization.
University researchers began to suspect that something was unusual when they couldn't get a constant melting point for sucrose in the work that they were doing.
The grooved feed-section temperature should be raised to 210 F, just below the melting point of the LLDPE.
Has a melting point of 217[degrees]C and a specific gravity of 7.
By incorporating the IncroMax in an Atmer material Croda says it has overcome problems associated with adding IncroMax 100 in its natural physical form, which is a low melting point solid.
Results of the research revealed that melting point of platinum nanoclusters increases as the number of particles available in the system decreases.
Stuart's new SMP40 automatic melting point apparatus incorporates the latest digital video imaging technology to detect and accurately capture the melting point of up to three samples simultaneously.
An element's melting point is the temperature at which it changes from a solid to a liquid.

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