Wednesday, November 27, 2019

Specific Heat Capacity Definition

Specific Heat Capacity Definition Specific Heat Capacity Definition Specific heat capacity is the amount of heat energy required to raise the temperature of a substance per unit of mass. The specific heat capacity of a material is a physical property. It is also an example of an extensive property since its value is proportional to the size of the system being examined.In ​SI units, specific heat capacity (symbol: c) is the amount of heat in joules required to raise 1 gram of a substance 1 Kelvin.   It may also be expressed as J/kg ·K. Specific heat capacity may be reported in the units of calories per gram degree Celsius, too. Related values are molar heat capacity, expressed in J/mol ·K, and volumetric heat capacity, given in J/m3 ·K. Heat capacity is defined as the ratio of the amount of energy transferred to a material and the change in temperature that is produced: C Q / ΔT where C is heat capacity, Q is energy (usually expressed in joules), and ΔT is the change in temperature (usually in degrees Celsius or in Kelvin). Alternatively, the equation may be written: Q CmΔT Specific heat and heat capacity are related by mass: C m * S Where C is heat capacity, m is mass of a material, and S is specific heat. Note that since specific heat is per unit mass, its value does not change, no matter the size of the sample. So, the specific heat of a gallon of water is the same as the specific heat of a drop of water. Its important to note the relationship between added heat, specific heat, mass, and temperature change does not apply during a phase change. The reason for this is because heat that is added or removed in a phase change does not alter the temperature. Also Known As: specific heat, mass specific heat, thermal capacity Specific Heat Capacity Examples Water has a specific heat capacity of 4.18 J (or 1 calorie/gram  °C). This is a much higher value than that of most other substances, which makes water exceptionally good at regulating temperature. In contrast, copper has a specific heat capacity of 0.39 J. Table of Common Specific Heats and Heat Capacities This chart of specific heat and heat capacity values should help you get a better sense of the types of materials that readily conduct heat versus those which do not. As you might expect, metals have relatively low specific heats. Material Specific Heat(J/gC) Heat Capacity(J/C for 100 g) gold 0.129 12.9 mercury 0.140 14.0 copper 0.385 38.5 iron 0.450 45.0 salt (Nacl) 0.864 86.4 aluminum 0.902 90.2 air 1.01 101 ice 2.03 203 water 4.179 417.9 Sources Halliday, David; Resnick, Robert (2013).  Fundamentals of Physics. Wiley. p.  524.Kittel, Charles (2005). Introduction to Solid State Physics (8th Ed.). Hoboken, New Jersey, USA: John Wiley Sons. p. 141. ISBN 0-471-41526-X.Laider, Keith J. (1993). The World of Physical Chemistry. Oxford University Press. ISBN 0-19-855919-4.unus A. Cengel and Michael A. Boles (2010). Thermodynamics: An Engineering Approach (7th Edition). McGraw-Hill. ISBN 007-352932-X.

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