Specific Heats for Gases

November 29, 2022 One-minute read

Since specific heat of a gas depends very much on how a process of changing its temperature is performed, there are specific heat of gases kept at constant temperature ( $c_P$ ) and at constant volume ( $c_V$ ), where some values are given as follow.

Gas	$c_P$ (kcal/kg $\cdot$ C $^\circ$ )	$c_V$ (kcal/kg $\cdot$ C $^\circ$ )
Steam ( $100 ^\circ \rm C$ )	0.482	0.350
Oxygen	0.218	0.155
Helium	1.15	0.75
Carbon dioxide	0.199	0.153
Nitrogen	0.248	0.177

Notice that $c_P$ is always greater than $c_V$ for gases. This distinction is usually negigible for liquids and solids.

Douglas C. Giancoli, “Physics: Principles with Applications”, Pearson Education Inc., Boston, 7th Edition, Dec 2013, p. 394, url https://isbnsearch.org/isbn/9780321625922.