Specific heat capacity: Difference between revisions
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[[File:boilingwata.jpg|300px|thumb|Figure 1. Water has a specific heat capacity of 4.186 J/g°C, meaning that it requires 4.186 J of energy (1 calorie) to heat a gram by one degree.<Ref>Wikimedia Commons [Online], Available: http://upload.wikimedia.org/wikipedia/commons/1/18/Kochendes_wasser02.jpg</ref>]] | [[File:boilingwata.jpg|300px|thumb|Figure 1. Water has a specific heat capacity of 4.186 J/g°C, meaning that it requires 4.186 J of energy (1 calorie) to heat a gram by one degree.<Ref>Wikimedia Commons [Online], Available: http://upload.wikimedia.org/wikipedia/commons/1/18/Kochendes_wasser02.jpg</ref>]] | ||
<onlyinclude>'''Specific heat capacity''' is the amount of [[heat]] needed to raise one [[gram]] of a material by one degree [[celsius]] (<sup>o</sup>C).</onlyinclude><ref>UC Davis Chemwiki, ''Heat Capacity'' [Online], Available: http://chemwiki.ucdavis.edu/Physical_Chemistry/Thermodynamics/Calorimetry/Heat_Capacity#Specific_Heat_Capacity</ref> It is expressed in [[Joule]]s per gram per degree celsius (< | <onlyinclude>'''Specific heat capacity''' is the amount of [[heat]] needed to raise one [[gram]] of a material by one degree [[celsius]] (<sup>o</sup>C).</onlyinclude><ref>UC Davis Chemwiki, ''Heat Capacity'' [Online], Available: http://chemwiki.ucdavis.edu/Physical_Chemistry/Thermodynamics/Calorimetry/Heat_Capacity#Specific_Heat_Capacity</ref> It is expressed in [[Joule]]s per gram per degree celsius (<math>\frac{J}{g\times ^oC}</math>), and is given by the equation:<ref name=hyp>Hyperphysics, ''Specific Heat'' [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/spht.html</ref> | ||
<center>< | <center><math>c=\frac{Q}{m\Delta T}</math></center> | ||
where | where | ||
* < | * <math>c</math> is the specific heat, | ||
* < | * <math>Q</math> is the heat needed, | ||
* < | * <math>m</math> is the mass and | ||
* < | * <math>\Delta T</math> is the change in temperature of the system. | ||
This equation does not apply if a phase change is encountered, because the heat added or removed during a phase change does not change the temperature.<ref name=hyp/> | This equation does not apply if a phase change is encountered, because the heat added or removed during a phase change does not change the temperature.<ref name=hyp/> | ||
The specific heat for water is < | The specific heat for water is <math>c=4.186 \frac{J}{g\times ^oC}</math>, which gives the definition of the [[calorie]], and is relatively high compared to other common substances. As a result, water plays a very important role in temperature regulation.<ref name=hyp/> | ||
The third law of thermodynamics shows that as an object approaches [[absolute zero]], its specific heat capacity gets greater and greater, with the consequence that although substances can get very close to this temperature, nothing will ever reach it.<Ref>B. Everett, G. Boyle, S. Peake and J. Ramage, "Heat to motive power," in ''Energy Systems and Sustainability'', 2nd ed., Oxford, UK: Oxford, 2013, ch.6, pp.187</ref> | The third law of thermodynamics shows that as an object approaches [[absolute zero]], its specific heat capacity gets greater and greater, with the consequence that although substances can get very close to this temperature, nothing will ever reach it.<Ref>B. Everett, G. Boyle, S. Peake and J. Ramage, "Heat to motive power," in ''Energy Systems and Sustainability'', 2nd ed., Oxford, UK: Oxford, 2013, ch.6, pp.187</ref> | ||
Revision as of 22:34, 11 May 2018
Figure 1. Water has a specific heat capacity of 4.186 J/g°C, meaning that it requires 4.186 J of energy (1 calorie) to heat a gram by one degree.[1]
Specific heat capacity is the amount of heat needed to raise one gram of a material by one degree celsius (oC).[2] It is expressed in Joules per gram per degree celsius (), and is given by the equation:[3]
where
- is the specific heat,
- is the heat needed,
- is the mass and
- is the change in temperature of the system.
This equation does not apply if a phase change is encountered, because the heat added or removed during a phase change does not change the temperature.[3]
The specific heat for water is , which gives the definition of the calorie, and is relatively high compared to other common substances. As a result, water plays a very important role in temperature regulation.[3]
The third law of thermodynamics shows that as an object approaches absolute zero, its specific heat capacity gets greater and greater, with the consequence that although substances can get very close to this temperature, nothing will ever reach it.[4]
References
- ↑ Wikimedia Commons [Online], Available: http://upload.wikimedia.org/wikipedia/commons/1/18/Kochendes_wasser02.jpg
- ↑ UC Davis Chemwiki, Heat Capacity [Online], Available: http://chemwiki.ucdavis.edu/Physical_Chemistry/Thermodynamics/Calorimetry/Heat_Capacity#Specific_Heat_Capacity
- ↑ 3.0 3.1 3.2 Hyperphysics, Specific Heat [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/spht.html
- ↑ B. Everett, G. Boyle, S. Peake and J. Ramage, "Heat to motive power," in Energy Systems and Sustainability, 2nd ed., Oxford, UK: Oxford, 2013, ch.6, pp.187
