Question

3 mole of hydrogen is mixed with 1 mole of neon. The molar specific heat at constant pressure is

• A. $\frac{9R}{4}$
• B. $\frac{9R}{2}$
• C. $\frac{13R}{4}$
• D. $\frac{13R}{2}$

Answer 1

Answer: (C)

For mixture, $C_V=\frac{n_1{C}_{V_1}+n_2{C}_{V_2}}{n_1+n_2}$
$=\frac{3\times \frac{5}{2}R+1\times \frac{3}{2}R}{3+1}=\frac{9R}{4}$
$C_p=C_V+R=\frac{9R}{4}+R=\frac{13R}{4}$