Question

The ratio C_P/C_V for a gas mixture consisting of $8g$ of helium and $16g$ of oxygen is :

• A. $15/23$
• B. $17/27$
• C. $23/15$
• D. $27/17$

Answer 1

Answer: (D)

${\gamma }_{mix}=\frac{n_{1}C{p}_1+n_{2}C{p}_2}{n_{1}C{v}_1+n_{2}C{v}_2}$
${\gamma }_{\mathrm{mix}}=\frac{(2)\left(\frac{5}{2}\right)+\left(\frac{1}{2}\right)\left(\frac{7}{2}\right)}{(2)\left(\frac{3}{2}\right)+\frac{1}{2}\left(\frac{5}{2}\right)}=\frac{10+\frac{7}{2}}{6+\frac{5}{2}}=\frac{27}{17}$