Relationships between the principal specific heats for a near-ideal gas

1 Relationships between the principal specific heats for a near-ideal gas 

Differentiating equation (3.17) with respect to temperature for a near-ideal gas when Z is constant gives  

We can proceed further, since the kinetic theory of gases gives us the result for a near-ideal gas that  

The ratio, y, of the principal specific heats of a gas is of importance in expansion and compression processes, since it may be shown that a reversible, adiabatic (isen-tropic) expansion or compression will obey the law  

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