Melting point: Difference between revisions
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[[File:ice-263823_640.jpg|300px|thumb|Figure 1. Pure water has a melting point of 0°C, which allows one to test any other sample of water to check its purity.<ref>tedrafranklin, Pixabay [Online], Available: http://pixabay.com/p-263823/?no_redirect</ref>]] | [[Category:Translated to Spanish]] | ||
[[es:Punto de fusión]] | |||
<onlyinclude>[[File:ice-263823_640.jpg|300px|thumb|Figure 1. Pure water has a melting point of 0°C, which allows one to test any other sample of water to check its purity.<ref>tedrafranklin, Pixabay [Online], Available: http://pixabay.com/p-263823/?no_redirect</ref>]]'''Melting point''' is the [[temperature]] at which a [[solid]] will [[phase change|change phase]] into a [[liquid]].</onlyinclude> In theory it will also be the same temperature as the ''freezing point'', where a liquid will turn into a solid, but in practice there are slight differences.<ref name="pur">Purdue Chemistry, ''Melting point, Freezing point, Boiling point'' [Online], Available: http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch14/melting.php#melt</ref> For example, in theory pure water has a melting point ''and'' freezing point at [[Celsius|0°C]] under [[STP|standard temperature and pressure]], but slight measurable differences tend to arise. | |||
The transition between the solid and the liquid is so sharp for small samples of a pure substance that melting points can be measured to 0.1°C.<ref name="pur" /> Therefore melting points can be used to accurately measure the purity of a substance.<ref>Encyclopaedia Brittanica, ''Melting point'' [Online], Available: http://www.britannica.com/EBchecked/topic/374185/melting-point</ref> See Figure 1 on the right. | |||
While the solid is in the process | While the solid is in the process of melting, its temperature will not change (see Figure 2 below). This is known as [[latent heat]], which is the opposite of [[sensible heat]]. | ||
[[File:Ating-20curve-20of-20water1.jpg|left|thumb|Figure 2. This is a heating curve diagram, specifically for water.<ref>Lumen Learning (2015). (Accessed July 29, 2026). ''Introduction to Chemistry: Heating Curve for Water'' [Online]. Available: https://www.collegesidekick.com/study-guides/introchem/heating-curve-for-water</ref> Notice how temperature (on the y-axis) stays constant during a phase change. This is because the heat absorbed (x-axis) is being used to weaken intermolecular bonds instead of accumulating as kinetic energy.]] | |||
== For Further Reading == | |||
* [[Temperature]] | |||
* [[Phase change]] | |||
* [[Standard conditions for temperature and pressure]] | |||
* [[Latent heat]] | |||
* [[Sensible heat]] | |||
* Or explore a [[Special:Random|random page]] | |||
==References== | ==References== | ||
{{reflist}} | {{reflist}} | ||
[[Category:Uploaded]] | [[Category:Uploaded]] | ||
Latest revision as of 20:43, 4 August 2026
Figure 1. Pure water has a melting point of 0°C, which allows one to test any other sample of water to check its purity.[1]
Melting point is the temperature at which a solid will change phase into a liquid. In theory it will also be the same temperature as the freezing point, where a liquid will turn into a solid, but in practice there are slight differences.[2] For example, in theory pure water has a melting point and freezing point at 0°C under standard temperature and pressure, but slight measurable differences tend to arise.
The transition between the solid and the liquid is so sharp for small samples of a pure substance that melting points can be measured to 0.1°C.[2] Therefore melting points can be used to accurately measure the purity of a substance.[3] See Figure 1 on the right.
While the solid is in the process of melting, its temperature will not change (see Figure 2 below). This is known as latent heat, which is the opposite of sensible heat.
Figure 2. This is a heating curve diagram, specifically for water.[4] Notice how temperature (on the y-axis) stays constant during a phase change. This is because the heat absorbed (x-axis) is being used to weaken intermolecular bonds instead of accumulating as kinetic energy.
For Further Reading
- Temperature
- Phase change
- Standard conditions for temperature and pressure
- Latent heat
- Sensible heat
- Or explore a random page
References
- ↑ tedrafranklin, Pixabay [Online], Available: http://pixabay.com/p-263823/?no_redirect
- ↑ 2.0 2.1 Purdue Chemistry, Melting point, Freezing point, Boiling point [Online], Available: http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch14/melting.php#melt
- ↑ Encyclopaedia Brittanica, Melting point [Online], Available: http://www.britannica.com/EBchecked/topic/374185/melting-point
- ↑ Lumen Learning (2015). (Accessed July 29, 2026). Introduction to Chemistry: Heating Curve for Water [Online]. Available: https://www.collegesidekick.com/study-guides/introchem/heating-curve-for-water