Relation between specific heats | Formula

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In this article, you will learn the relations between two specific heats Cp and Cv. 

Relations between specific heats: 


  • The difference between two specific heats is equal to a gas constant. 
Cp - Cv = R 
  • The ratio of two specific heats is known as an adiabatic index and it denoted as ϒ.
We know above equation, Cp - Cv = R 

Cp / Cv = 1 + R / Cv 

Now we take Cp / Cv = ϒ

ϒ = 1 + R / Cv

As we have seen in the article Why is the specific heat at constant pressure greater than specific heat at constant volume? We all know that Cp is always greater than Cv therefore the value of ϒ is always greater than unity. 

The value of ϒ for air is 1.4. 

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