Question

Equal volumes of monoatomic and diatomic gases of same initial temperature and pressure are mixed. The ratio of the specific heats of the mixture ($C_p/C_v$) will be

• A. $1.53$
• B. $1.52$
• C. $1.5$
• D. $1$

Answer 1

Answer: (C)

$1.5$

$C_p$ for a gas is given as $(1+\frac{f}{2})R$ and $C_v$ is given as $\frac{f}{2}R$. Here f is the degree of freedom.

For monoatomic gas it is 3 and for a diatomic gas it is 5.

Thus, we get $C_p$ for the mixture as $\frac{5}{2}R+\frac{7}{2}R=6R$ and $C_v$ is given as $\frac{3}{2}R+\frac{5}{2}R=4R$.
Thus, the ratio $\frac{C_p}{C_v}$ is given as $\frac{3}{2}=1.5$