Question

One mole of monoatomic gas and three moles of diatomic gas are put together in a container. The molar specific heat (in $JK^{- 1}mol^{- 1})$ at constant volume is $(R = 8.3JK^{- 1}mol^{- 1})$

• A. 18.7
• B. 18.9
• C. 19.2
• D. None of the above

Answer 1

Answer: (A)

18.7

Answer 2

$C_{V_{\text{mix}}} = \frac{\mu_{1}C_{V_{1}} + \mu_{2}C_{V_{2}}}{\mu_{1} + \mu_{2}} = \frac{1 \times \frac{3}{2}R + 3 \times \frac{5}{2}R}{1 + 3}$

$= \frac{3}{4}R = \frac{3}{4} \times 8.3 = 18.7$