Question

The ratio of the molar heat capacities of a diatomic gas at constant pressure to that at constant volume is

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

Answer 1

Answer: (A)

$\frac{7}{5}$

Answer 2

For a diatomic gas, Molar heat capacity at constant pressure,

$C_{p} = \frac{7}{4}R$

Molar heat capacity at constant volume $C_{r} = \frac{5}{2}R$

$\therefore\frac{C_{P}}{C_{V}} = \frac{7/2R}{5/2R} = 7/5$