Question

In gases of diatomic molecules, the ratio of two specific heats of gases $\frac{C_p}{C_v}$ is:

• A. 1.21
• B. 1.33
• C. 2.80
• D. 1.40

Answer 1

Answer: (D)

The specific heat of diatomic gas at constant pressure
$C_P=\frac{7}{2}R\dots (1)$
and specific heat of diatomic gases at constant volume
$C_v=\frac{5}{12}R\dots (2)$
Hence, from quation (1) and (2) we get
$\frac{C_p}{C_v}=\frac{\frac{7}{2}R}{\frac{5}{2}R}$
$=\frac{7}{5}=1.4$