Question

A mixture of one mole of a monoatomic gas and one mole of a diatomic gas (rigid) are kept at room temperature ($27^\circ \text{C}$). The ratio of specific heat of gases at constant volume respectively is:

• A. $\frac{7}{5}$
• B. $\frac{3}{2}$
• C. $\frac{3}{5}$
• D. $\frac{5}{3}$

Answer 1

Answer: (C)

$\frac{3}{5}$

Answer 2

The specific heat capacities at constant volume are:
$(C_V)_{\text{mono}} = \frac{3}{2}R, \quad (C_V)_{\text{dia}} = \frac{5}{2}R.$
The ratio is:
$\frac{(C_V)_{\text{mono}}}{(C_V)_{\text{dia}}} = \frac{\frac{3}{2}R}{\frac{5}{2}R} = \frac{3}{5}.$
Final Answer: $3 : 5$.