Question

The molar heat capacity of a gas at constant volume is $5{\text{cal mol}}^{-1}{\text{K}}^{-1}$. Find the value of $\gamma$ for the gas if the gas constant, $R=2{\text{cal mol}}^{-1}{\text{K}}^{-1}$.

• A. $1.66$
• B. $1.4$
• C. $1.33$
• D. $1.8$

Answer 1

The correct option is B $1.4$

Given, $C_V=5{\text{cal mol}}^{-1}{\text{K}}^{-1}$
We know,
$C_p-C_V=R$
$\Rightarrow C_p=C_V+R=7{\text{cal mol}}^{-1}{\text{K}}^{-1}$
$\therefore \gamma =\frac{C_p}{C_v}=\frac{7}{5}=1.4$