Question

$2mol$ of $He$ is mixed with $2gm$ of $H_2$. The molar heater capacity at constant pressure for the mixture is :

• A. $\frac{17R}{6}$
• B. $\frac{11R}{6}$
• C. $4R$
• D. $\frac{3R}{2}$

Answer 1

The correct option is A $\frac{17R}{6}$

Given that:
$C_{P_1}$ for $He=\frac{5}{2}R;C_{P_2}$ for $H_2=\frac{7}{2}R$

$n_{He}=2;n_{H_2}=1$

$C_P=\frac{n_1{C}_{P_1}+n_2{C}_{P_1}}{n_1+n_2}=\frac{2\times \frac{5}{2}R+1\times \frac{7}{2}R}{3}$

$=\frac{17R}{6}$

Hence, the correct option is A.