Question

The molar heat capacity at constant volume of argon, Ar, is 12.47 J K mol-1. What is the value of the molar heat capacity at constant pressure?

Answer 1

We know, the relation between molar specific heat capacity at constant volume and constant pressure ,
e.g., $C_p-C_v=R$
where Cv is molar specific heat capacity at constant volume.
Cp is the molar specific heat capacity at constant pressure.

Given, Cv = 12.47 J/K/mol and we know, R = 8.31 J/K/mol
so, Cp = Cv + R
= 12.47 + 8.31 = 20.78 J/K/mol

Hence , answer is 20.78 J/K/mol