Specific Heat Capacity of Solids and Liquids

If $\Delta Q$ is the heat absorbed or released by a substance of mass $m$ undergoing a temperature change $\Delta T$, its specific heat capacity is defined by

so that if $m=1\text{ kg}$ and $\Delta T = 1\,°\text{C}$, then $s = \Delta Q$: specific heat capacity is the heat needed per unit mass to change temperature by one degree (1 °C or 1 K). Its SI unit is $\text{J kg}^{-1}\text{K}^{-1}$ (or J/kg °C), and the CGS unit is erg/g °C or erg/g K. Specific heat capacity is essentially constant over ordinary temperature ranges (it depends only weakly on temperature, except close to very low temperatures).

If the amount of substance is expressed in moles $\mu$ rather than mass $m$, the analogous quantity is the molar specific heat:

$C = \frac{\Delta Q}{\mu\,\Delta T} \quad \text{--- (7.27)}$ …