Molar heat capacity of gas

[Emma Li 2C]

Could you explain why gas has two values for molar heat capacity?

Thank you!

[Gianna Apoderado 1B]

Gas has two molar heat capacities because there is one for constant volume (Cv) and one for contant pressure (Cp) !

[torieoishi1A]

Gas has two values for molar heat capacity because one accounts for the constant volume process (Cv) and the other is the constant pressure process (Cp). Cv is the change in internal energy (U) with respect to to change in temperature at a fixed volume whereas Cp is the change in enthalpy (H) with respect to change in temperature at a fixed pressure. Liquids and solids are basically non compressible, therefore Cp and Cv are essentially equal since only one value of specific heat is used to calculate them.

[Caroline LaPlaca]

Constant volume and constant pressure are two different situations for a gas. Therefore, there must be two different values for molar heat capacity of gas.