The relation Cp - C v = R (Cp and Cv are the molar specific heats at constant pressure and volume) is exactly true for

Question

The relation Cp - C v = R (Cp and Cv are the molar specific heats at constant pressure and volume) is exactly true for (A) an ideal monoatomic gas (B) any ideal gas, whether monoatomic, diatomic or polyatomic (C) any real gas above its critical temperature (D) All real gases

Tardigrade Admin · Accepted Answer

Mayer’s relation, Cp - Cv = R is true only for ideal gases whether they are monoatomic, diatomic or polyatomic as for real gases. Cp - CV = TVβ2k where, k = isothermal compressibility and β = isobaric thermal expansion coefficient.

Q. The relation $C_{p} - C v = R (C_{p}$ and $C_{v}$ are the molar specific heats at constant pressure and volume) is exactly true for

an ideal monoatomic gas

any ideal gas, whether monoatomic, diatomic or polyatomic

any real gas above its critical temperature

All real gases

Mayer’s relation,
$C_{p} - C_{v} = R$ is true only for ideal gases whether they are monoatomic,
diatomic or polyatomic as for real gases.
$C_{p} - C_{V} = T V β^{2} k$
where, $k =$ isothermal compressibility
and $β =$ isobaric thermal expansion coefficient.

Q. The relation Cp​−Cv=R(Cp​ and Cv​ are the molar specific heats at constant pressure and volume) is exactly true for