Question

If one mole of a polyatomic gas has two vibrational modes and β is the ratio of molar specific heats for polyatomic gas β=C_p / C_v then the value of β is.

• A. 1.35
• B. 1.02
• C. 1.25
• D. 1.2

Answer 1

The correct option is D

1.2

Explanation for the correct option:

If one mole of the polyatomic gas is having two vibrational modes and $\beta$ is the ratio of molar specific heat for polyatomic gas ($\beta =\frac{CP}{CV})$ then the value of $\beta$ is:

$$\begin{gathered} \beta =\frac{C_p}{C_v} \\ \Rightarrow \beta =1+\frac{2}{f} \\ \Rightarrow \beta =\frac{12}{10} \\ \Rightarrow \beta =\frac{12}{10} \\ \Rightarrow \beta =1.2 \end{gathered}$$

Final Answer: Hence, the correct answer is an option (D).