Question

Specific heat capacity at constant volume of one mole diatomic ideal gas is

• A. $2R$
• B. $1.5R$
• C. $R$
• D. $2.5R$

Answer 1

The correct option is D $2.5R$

Given,
$n=1$
$f=5$ (Diatomic Gas)
We know internal energy $\left(U\right)$-
$U=\frac{nfRT}{2}$
Now, $C_v=\frac{\partial U}{\partial T}=\frac{nfR}{2}$
$\Rightarrow C_v=\frac{1\times 5\times R}{2}$
$\Rightarrow C_v=2.5R$