Question

The ratio of the adiabatic to isothermal elasticities of a triatomic gas is:

• A. $\frac{3}{4}$
• B. $\frac{4}{3}$
• C. $1$
• D. $\frac{5}{3}$

Answer 1

The correct option is B $\frac{4}{3}$

The value of $C_v=\frac{6}{2}R$ for triatomic gas

Also $C_p=C_v+R=\frac{6}{2}R+R=\frac{8}{2}R$

$C_p\text{and}{C}_V$ are the specific heat of gas in constant pressure and constant volume.

The ratio of adiabatic elasticity to isothermal elasticity gives us the constant $\gamma$

Also $\gamma =\frac{C_p}{c_v}=\frac{\frac{8}{2}R}{\frac{6}{2}R}=\frac{4}{3}$