Question

If $2moles$ of diatomic gas and $1mole$ of monatomic gas are mixed, then the ratio of specific heats for the mixture is

• A. $\frac{7}{3}$
• B. $\frac{5}{4}$
• C. $\frac{19}{13}$
• D. $\frac{15}{19}$

Answer 1

Answer: (C)

$\frac{19}{13}$

Average degree of freedom $=f=\frac{\left(2\right)\left(5\right)+\left(1\right)\left(3\right)}{2+1}=\frac{13}{3}$

Thus $\frac{C_p}{C_v}=\frac{\frac{f}{2}+1}{\frac{f}{2}}=\frac{19}{13}$