Question

Two moles of monoatomic gas is mixed with one mole of diatomic gas at the same temperature. Molar heat capacity at constant volume for the mixture is –

• A. $\frac{13R}{6}$
• B. $\frac{11R}{6}$
• C. $\frac{5R}{3}$
• D. $\frac{7R}{6}$

Answer 1

Answer: (B)

$\frac{11R}{6}$

Answer 2

$\frac{n_{1}{c_{v}}_{1} + n_{2}{c_{v}}_{2}}{n_{1} + n_{2}}$= (c_v)_mix = $\frac{2 \times \frac{3}{2}R + 1 \times \frac{5}{2}R}{2 + 1}$ = $\frac{3R + \frac{5}{2}R}{3}$

= $\frac{11R}{6}$