Question 385: Thermodynamics & KTG

Question

If one mole of the polyatomic gas is having two vibrational modes and $$\beta$$ is the ratio of molar specific heats for polyatomic gas $$\left( {\beta  = {{{C_P}} \over {{C_V}}}} \right)$$ then the value of $$\beta$$ is :

Accepted Answer

For polyatomic gas molecule has 3 rotational degrees of freedom,
3 translational degrees of freedom, and 2 vibrational modes.
So, number of vibrational degrees of freedom = 2 $$ 	imes $$ 2 = 4
Degree of freedom of polyatomic gas
f = T + R + V
f = 3 + 3 + 4 = 10
$$\beta  = 1 + {2 \over f} = 1 + {2 \over 10}$$
$$\beta  = {{12} \over 10} = 1.2$$

Answer

1.02

Answer

1.35

Answer

1.2

Answer

1.25

Thermodynamics & KTG

If one mole of the polyatomic gas is having two vibrational modes and $\beta is the ratio of molar specific heats for polyatomic gas \left( {\beta = {{{C_P}} \over {{C_V}}}} \right) then the value of \beta$ is :

Choose the correct answer: