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Heat Capacity Research Paper

Heat Capacity is defined by Robinson and Haas (1983) as the quantity of heat that is required to raise the temperature of a unit quantity of a given substance by one degree Kelvin at a constant pressure. A brief history of the concept

Prior to the development of the modern theories of thermodynamics, it was widely thought that heat was some form of a fluid called calorific (Cengel, 2007).Different bodies were capable of effectively holding a certain quantity of this fluid and their ability to hold such a fluid was referred to as heat capacity as was initially investigated by one Joseph Black in 1750s (Laider,1993).In this age and time, we discuss the concept of the internal energy system. This comprises of microscopic kinetic as well as potential energy. Heat too is never considered as a fluid but is regarded as a transfer of energy which is disordered at a microscopic level.

The theory of heat capacity

Heat capacity (C) a term which is otherwise referred to as thermal capacity is the physical quantity which is measurable and that characterizes the amount of heat that is required in order to change the temperature of a substance by a specific amount. In terms of the International Systems of Unites (SI), the concept of heat capacity is denoted in unites of joule(s) (J) per kelvin (K).

There are several derived quantities that are used in the specification of the concept of heat capacity as a physical quantity with intensive property. This is to say that the quantity is expressed as an independent one in regard to the sample size. These are known as molar heat capacity a concept which refers to the heat capacity per mole of a given pure substance, Specific heat capacity...

Temperature on the other hand expresses the average kinetic energy of a given particulate matter. Heat is however the transfer of thermal energy and denotes a floe of this energy from a region of high temperature to a region of low temperature.
Storage of thermal energy

Thermal energy is usually stored as kinetic energy in the rather random mode of translation in the monatomic substances as well as translations coupled with rotations of polyatomic molecules in the gaseous state.

Thermal energy may also be stored in the form of potential energy. This energy is closely associated with the higher modes of atomic vibrations in cases where they occur in a substance's interactomic bonds. A degree of freedom is however presented by the rotation, translation as well as any other combination of the various types of energy in vibration (potential and kinetic). There represent a degree of freedom of motion that is known to classically make part of the hat capacity of any given thermodynamic system.

On a microscopic scale, each and every particle in a given system effectively absorbs certain quantity of heat energy within the degree of freedom that it has. This form of absorption is noted to contribute in part to the specific heat capacity which in the classical sense of things approaches a mixum quantity per mole of particles as denoted by the Dulong-Pett law. This limit is usually 25 joules per Kelvin for every mole of atoms in a given crystalline structure.

Heat…

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References

Cengel, Y.A (2007). Introduction To Thermodynamics and Heat Transfer.MacGraw Hill

Laider, K.J. (1993). The World of Physical Chemistry. Oxford University Press. ISBN 0-19-855919-4.

Roninson, G, R and Hass, J.L (1983)Heat capacity, relative enthalpy, and calorimetric entropy of silicate minerals: an empirical method of prediction. American Mineralogist, Volume 68, pages 541-553, 1983
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