Specific Heat of Solids

**Category : **JEE Main & Advanced

When a solid is heated through a small range of temperature, its volume remains more or less constant. Therefore specific heat of a solid may be called its specific heat at constant volume \[{{C}_{V}}\].

(1) From the graph it is clear that at \[T=0,\,\,{{C}_{V}}\] tends to zero

(2) With rise in temperature, \[{{C}_{V}}\] increases and at a particular temperature (called Debey's temperature) it becomes constant = 3R = 6 cal/mole \[\times \] kelvin = 25 J/mole \[\times \] kelvin

(3) For most of the solids, Debye temperature is close to room temperature.

(4) Dulong and Petit law : Average molar specific heat of all metals at room temperature is constant, being nearly equal to 3R = 6 cal. \[mol{{e}^{-1}}\,{{K}^{-1}}\] = 25 J \[mol{{e}^{-1}}\,{{K}^{-1}}\], where R is gas constant for one mole of the gas. This statement is known as Dulong and Petit law.

(5) Debey's law : It was observed that at very low temperature molar specific heat \[\propto {{T}^{3}}\] exception are Sn, Pb and Pt)

(6) Specific heat of ice : In C.G.S. \[{{c}_{\text{ice}}}=0.5\,\frac{cal}{gm\times {}^\circ C}\]

In S.I. \[{{c}_{ice}}==500\,\frac{cal}{kg\times {}^\circ C}=2100\,\frac{Joule}{kg\times {}^\circ C}\].

**Specific heat of some solids at room temperature and atmospheric pressure**

Substance |
Specific heat \[\mathbf{(J-k}{{\mathbf{g}}^{\mathbf{-1}}}\,{{\mathbf{K}}^{\mathbf{-1}}}\mathbf{)}\] |
Molar specific heat \[\mathbf{(J-g}\,\,\mathbf{mol}{{\mathbf{e}}^{\mathbf{-1}}}\,{{\mathbf{K}}^{\mathbf{-1}}}\mathbf{)}\] |

Aluminium | 900.0 | 24.4 |

Copper | 386.4 | 24.5 |

Silver | 236.1 | 25.5 |

Lead | 127.7 | 26.5 |

Tungsten | 134.4 | 24.9 |

*play_arrow*Temperature*play_arrow*Thermometry*play_arrow*Thermometers*play_arrow*Thermal Expansion*play_arrow*Scales of Temperature*play_arrow*Application of Thermal Expansion in Solids*play_arrow*Thermal Expansion in Liquids*play_arrow*Variation of Density with Temperature*play_arrow*Expansion of Gases*play_arrow*Heat*play_arrow*Specific Heat*play_arrow*Specific Heat of Solids*play_arrow*Specific Heat of Liquid (Water)*play_arrow*Specific Heat of Gases*play_arrow*Phase Change and Latent Heat*play_arrow*Thermal Capacity and Water Equivalent*play_arrow*Some Important Terms*play_arrow*Joule's Law (Heat and Mechanical Work)*play_arrow*Principle of Calorimetry*play_arrow*Heating Curve

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